WorldWideScience

Sample records for nonnutrient germinants dodecylamine

  1. Recycling dodecylamine intercalated vanadate nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Odair P., E-mail: odair@iqm.unicamp.br; Souza Filho, Antonio G., E-mail: agsf@fisica.ufc.br; Alves, Oswaldo L., E-mail: oalves@iqm.unicamp.b [Universidade Estadual de Campinas-UNICAMP, LQES - Laboratorio de Quimica do Estado Solido, Instituto de Quimica (Brazil)

    2010-01-15

    In this article, we report the thermal decomposition processes of dodecylamine intercalated vanadate nanotubes and their recycling process. Structural, vibrational, and morphological properties of the annealed samples were investigated by X-ray diffraction, infrared spectroscopy, and scanning electron microscopy, respectively. The data analysis unveiled that vanadate nanotubes (VONTs) decompose into nanoplates which is isostructural to xerogel, and finally to nanoparticle aggregates whose composition is a single V{sub 2}O{sub 5} bulk phase. These aggregates can be successfully recycled for converting the residues of decomposition process into vanadate nanotubes again.

  2. Dodecylamine-loaded halloysite nanocontainers for active anticorrosion coatings

    Science.gov (United States)

    Falcón, Jesus; Sawczen, Tiago; Aoki, Idalina

    2015-11-01

    Currently the most promising approach in the corrosion protection by smart coatings is the use of nanoreservoirs loaded with corrosion inhibitors. Nanocontainers are filled with anti-corrosive agents and embedded into a primer coating. Future prospective containers are halloysite nanotubes due to their low price, availability, durability, with high mechanical strength and biocompatibility. The aim of this work is to study the use of halloysite nanotubes as nanocontainers for encapsulated dodecylamine for active corrosion protection of carbon steel. Halloysite clay was characterized by XRD and TGA- thermogravimetric analysis techniques. Halloysite nanotubes were loaded with dodecylamine and embedded into an alkyd primer with a weight ratio of 10 wt.% . The anticorrosive performance of the alkyd primer doped with 10 wt.% of entrapped-dodecylamine halloysite was tested on coated carbon steel by direct exposure of the coated samples with a provoked defect into 0.01 mol/L NaCl corrosive media using electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET). EIS and SVET measurements showed the self-healing properties of the doped alkyd coating. Coated samples were also evaluated in a salt spray chamber and the self-healing effect was unequivocally noticed.

  3. Dodecylamine-loaded halloysite nanocontainers for active anticorrosion coatings

    Directory of Open Access Journals (Sweden)

    Jesus Marino Falcón

    2015-11-01

    Full Text Available Currently the most promising approach in the corrosion protection by smart coatings is the use of nanoreservoirs loaded with corrosion inhibitors. Nanocontainers are filled with anti-corrosive agents and embedded into a primer coating. Future prospective containers are halloysite nanotubes due to their low price, availability, durability, with high mechanical strength and biocompatibility. The aim of this work is to study the use of halloysite nanotubes as nanocontainers for encapsulated dodecylamine for active corrosion protection of carbon steel. Halloysite clay was characterized by XRD and TGA- thermogravimetric analysis techniques. Halloysite nanotubes were loaded with dodecylamine and embedded into an alkyd primer with a weight ratio of 10 wt.% . The anticorrosive performance of the alkyd primer doped with 10 wt.% of entrapped-dodecylamine halloysite was tested on coated carbon steel by direct exposure of the coated samples with a provoked defect into 0.01 mol/L NaCl corrosive media using electrochemical impedance spectroscopy (EIS and scanning vibrating electrode technique (SVET. EIS and SVET measurements showed the self-healing properties of the doped alkyd coating. Coated samples were also evaluated in a salt spray chamber and the self-healing effect was unequivocally noticed.

  4. Dietary non-nutrients and haemostasis in humans: effects of salicylates, flavonoids and ginger.

    NARCIS (Netherlands)

    Janssen, P.L.T.M.K.

    1997-01-01

    In this thesis we studied the content of acetylsalicylate and total salicylates in foods, and we studied the effects of the dietary non-nutrients salicylates and flavonoids and of certain foods on haemostatic parameters in humans.Acetylsalicylic acid -aspirin- irreversibly inhibits platelet cyclo-ox

  5. Comparative mapping of rice root traits in seedlings grown in nutrient or non-nutrient solution

    Institute of Scientific and Technical Information of China (English)

    XU Jichen; LI Xiaobo; ZHU Lihuang

    2004-01-01

    The component and amount of nutrient in the growth medium are the major factors affecting root growth.For the systematic dissection of root gene expression,evaluation of nutrient and non-nutrient solutions was conducted for their effect on root traits and quantitative trait loci(QTL)mapping.Three rice root parameters,maximum root length(MRL),root dry weight(RDW),and root/ shoot ratio of dry weight(RSR),were characterized within a double haploid(DH)population from a cross of ZYQ8(indica)and JX17(japonica).The value of the three root traits in two parents all decreased under the nutrient condition compared to those under the nonnutrient condition,of which RSR decreased up to 2.6-fold on average.In the DH population,more than 70 % lines in MRL,94 % lines in RDW,and all the lines in RSR were scored lower.In total,eight QTLs were identified in nutrient system(5 from JX17 alleles and 3 from ZYQ8 alleles)while five QTLs were detected in non-nutrient system(4 from JX17 alleles and 1 from ZYQ8 alleles).Of them,one QTL for RSR was shared by both culturing systems,seven QTLs were specific in nutrient system and the other four QTLs were specific in non-nutrient system.All 13 QTLs were distributed over 7 rice chromosomes-2,3,4,5,6,9 and 10,respectively.

  6. Dietary non-nutrients and haemostasis in humans : effects of salicylates, flavonoids and ginger

    NARCIS (Netherlands)

    Janssen, P.L.T.M.K.

    1997-01-01

    In this thesis we studied the content of acetylsalicylate and total salicylates in foods, and we studied the effects of the dietary non-nutrients salicylates and flavonoids and of certain foods on haemostatic parameters in humans.

    Acetylsalicylic acid -aspirin- irreversibly inhibits

  7. Molecular dynamics simulations of dodecylamine adsorption on iron surfaces in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Tang Yongming, E-mail: tangym@njut.edu.c [School of Science, Nanjing University of Technology, Nanjing 210009 (China); Yao Lala; Kong Chunmei; Yang Wenzhong [School of Science, Nanjing University of Technology, Nanjing 210009 (China); Chen Yizhong [School of Environmental and Safety Engineering, Jiangsu Polytechnic University, Changzhou 213164 (China)

    2011-05-15

    Research highlights: {yields} MD simulations results of the adsorption of DDA on iron surfaces are strongly related to the simulation conditions. {yields} DDAH is main adsorption form in strong acidic solution. {yields} Chloride ions play an important role on the adsorption of DDA in weak acidic solution. - Abstract: Molecular dynamics (MD) simulations have been used to study the adsorption of dodecylamine (DDA) on iron surfaces in aqueous solution in this paper. In strong acidic solution the protonated form of DDA, DDAH, can adsorb on the iron surface preferentially, while in weak acidic solution containing chloride ions the adsorption of DDA and DDAH forms can occur simultaneously. Different results were obtained when different simulation factors were considered. In order to obtain the correct results, a model close to the realistic inhibition system was fabricated.

  8. A dodecylamine derivative of cyanocobalamin potently inhibits the activities of cobalamin‐dependent methylmalonyl‐CoA mutase and methionine synthase of Caenorhabditis elegans

    National Research Council Canada - National Science Library

    Bito, Tomohiro; Yabuta, Yukinori; Ichiyanagi, Tsuyoshi; Kawano, Tsuyoshi; Watanabe, Fumio

    2014-01-01

    In this study, we showed that cyanocobalamin dodecylamine, a ribose 5′‐carbamate derivative of cyanocobalamin, was absorbed and accumulated to significant levels by Caenorhabditis elegans and was not further metabolized...

  9. A dodecylamine derivative of cyanocobalamin potently inhibits the activities of cobalamin-dependent methylmalonyl-CoA mutase and methionine synthase of Caenorhabditis elegans.

    Science.gov (United States)

    Bito, Tomohiro; Yabuta, Yukinori; Ichiyanagi, Tsuyoshi; Kawano, Tsuyoshi; Watanabe, Fumio

    2014-01-01

    In this study, we showed that cyanocobalamin dodecylamine, a ribose 5'-carbamate derivative of cyanocobalamin, was absorbed and accumulated to significant levels by Caenorhabditis elegans and was not further metabolized. The levels of methylmalonic acid and homocysteine, which serve as indicators of cobalamin deficiency, were significantly increased in C. elegans treated with the dodecylamine derivative, indicating severe cobalamin deficiency. Kinetic studies show that the affinity of the cyanocobalamin dodecylamine derivative was greater for two cobalamin-dependent enzymes, methylmalonyl-CoA mutase and methionine synthase, compared with their respective coenzymes, suggesting that the dodecylamine derivative inactivated these enzymes. The dodecylamine derivative did not affect the levels of mRNAs encoding these enzymes or those of other proteins involved in intercellular cobalamin metabolism, including methylmalonyl-CoA mutase (mmcm-1), methylmalonic acidemia cobalamin A complementation group (mmaa-1), methylmalonic aciduria cblC type (cblc-1), and methionine synthase reductase (mtrr-1). In contrast, the level of the mRNAs encoding cob(I)alamin adenosyltransferase (mmab-1) was increased significantly and identical to that of cobalamin-deficient C. elegans. These results indicate that the cyanocobalamin-dodecylamine derivative acts as a potent inhibitor of cobalamin-dependent enzymes and induces severe cobalamin deficiency in C. elegans.

  10. A dodecylamine derivative of cyanocobalamin potently inhibits the activities of cobalamin-dependent methylmalonyl-CoA mutase and methionine synthase of Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Tomohiro Bito

    2014-01-01

    Full Text Available In this study, we showed that cyanocobalamin dodecylamine, a ribose 5′-carbamate derivative of cyanocobalamin, was absorbed and accumulated to significant levels by Caenorhabditis elegans and was not further metabolized. The levels of methylmalonic acid and homocysteine, which serve as indicators of cobalamin deficiency, were significantly increased in C. elegans treated with the dodecylamine derivative, indicating severe cobalamin deficiency. Kinetic studies show that the affinity of the cyanocobalamin dodecylamine derivative was greater for two cobalamin-dependent enzymes, methylmalonyl-CoA mutase and methionine synthase, compared with their respective coenzymes, suggesting that the dodecylamine derivative inactivated these enzymes. The dodecylamine derivative did not affect the levels of mRNAs encoding these enzymes or those of other proteins involved in intercellular cobalamin metabolism, including methylmalonyl-CoA mutase (mmcm-1, methylmalonic acidemia cobalamin A complementation group (mmaa-1, methylmalonic aciduria cblC type (cblc-1, and methionine synthase reductase (mtrr-1. In contrast, the level of the mRNAs encoding cob(Ialamin adenosyltransferase (mmab-1 was increased significantly and identical to that of cobalamin-deficient C. elegans. These results indicate that the cyanocobalamin-dodecylamine derivative acts as a potent inhibitor of cobalamin-dependent enzymes and induces severe cobalamin deficiency in C. elegans.

  11. Synthesis of ZSM-5@Ordered Mesoporous Silica Composites by Dodecylamine Surfactant

    Institute of Scientific and Technical Information of China (English)

    MA Kuoyan; YU Haijun; FENG Guanglin; WANG Changguo; DAI Ya

    2014-01-01

    The core-shell structures of ZSM-5 coated with mesoporous silica were synthesized by means of dodecylamine (DDA) surfactant. The results show that the mesoporous silica shells are coated on ZSM-5 cores and result in the formation of hierarchical porous structures. The thickness of the coating shell can be controlled by changing the adding amount of TEOS. The core-shell composites with the thickness of 35 nm possess high surface areas (about 528 m2·g-1), large pores (about 3.5 nm in diameter) on the silica shells. The composite molecular sieves display higher adsorption capacity for benzene (140.2 mg·g-1) and butyraldehyde (213.7 mg·g-1) than that of pristine ZSM-5 for benzene (99.2 mg·g-1) and butyraldehyde (134.7 mg·g-1). The composite molecular sieves show a wide application foreground for harmful gas adsorbent for environmental protection.

  12. Kinetics of germination of individual spores of Geobacillus stearothermophilus as measured by raman spectroscopy and differential interference contrast microscopy.

    Directory of Open Access Journals (Sweden)

    Tingting Zhou

    Full Text Available Geobacillus stearothermophilus is a gram-positive, thermophilic bacterium, spores of which are very heat resistant. Raman spectroscopy and differential interference contrast microscopy were used to monitor the kinetics of germination of individual spores of G. stearothermophilus at different temperatures, and major conclusions from this work were as follows. 1 The CaDPA level of individual G. stearothermophilus spores was similar to that of Bacillus spores. However, the Raman spectra of protein amide bands suggested there are differences in protein structure in spores of G. stearothermophilus and Bacillus species. 2 During nutrient germination of G. stearothermophilus spores, CaDPA was released beginning after a lag time (T(lag between addition of nutrient germinants and initiation of CaDPA release. CaDPA release was complete at T(release, and DT(release (T(release - T(lag was 1-2 min. 3 Activation by heat or sodium nitrite was essential for efficient nutrient germination of G. stearothermophilus spores, primarily by decreasing T(lag values. 4 Values of T(lag and T(release were heterogeneous among individual spores, but DT(release values were relatively constant. 5 Temperature had major effects on nutrient germination of G. stearothermophilus spores, as at temperatures below 65°C, average T(lag values increased significantly. 6 G. stearothermophilus spore germination with exogenous CaDPA or dodecylamine was fastest at 65°C, with longer T(lag values at lower temperatures. 7 Decoating of G. stearothermophilus spores slowed nutrient germination slightly and CaDPA germination significantly, but increased dodecylamine germination markedly. These results indicate that the dynamics and heterogeneity of the germination of individual G. stearothermophilus spores are generally similar to that of Bacillus species.

  13. Non-Nutrient, Naturally Occurring Phenolic Compounds with Antioxidant Activity for the Prevention and Treatment of Periodontal Diseases

    Directory of Open Access Journals (Sweden)

    Alfonso Varela-López

    2015-06-01

    Full Text Available One of the main factors able to explain the pathophysiological mechanism of inflammatory conditions that occur in periodontal disease is oxidative stress. Given the emerging understanding of this relationship, host-modulatory therapies using antioxidants could be interesting to prevent or slow the breakdown of soft and hard periodontal tissues. In this context, non-nutrient phenolic compounds of various foods and plants have received considerable attention in the last decade. Here, studies focusing on the relationship between different compounds of this type with periodontal disease have been collected. Among them, thymoquinone, coenzyme Q (CoQ, mangiferin, resveratrol, verbascoside and some flavonoids have shown to prevent or ameliorate periodontal tissues damage in animal models. However evidence regarding this effect in humans is poor and only limited to topical treatments with CoQ and catechins. Along with animal experiments, in vitro studies indicate that possible mechanisms by which these compounds might exert their protective effects include antioxidative properties, oxygen and nitrogen scavenging abilities, and also inhibitory effects on cell signaling cascades related to inflammatory processes which have an effect on RNS or ROS production as well as on antioxidant defense systems.

  14. Fullerene films and fullerene-dodecylamine adduct monolayers at air-water interfaces studied by neutron and x-ray reflection

    DEFF Research Database (Denmark)

    Wang, J.Y.; Vaknin, D.; Uphaus, R.A.;

    1994-01-01

    Neutron and X-ray reflection measurements and surface pressure isotherms of spread films of the fullerene-dodecylamine adduct C60-[NH2(CH2)11CH3]x all indicate that this material may form monomolecular layers on water surfaces. The reflection data sets (neutron on both H2O and D2O) can be accounted...

  15. Study on the Chromatographic Behavior of Bases on Dodecylamine-N,N-dimethylenephosphonic Acid-Modified Zirconia Stationary Phase

    Institute of Scientific and Technical Information of China (English)

    Yao Lifeng; Feng Yuqi; Da Shilu

    2006-01-01

    A new zirconia-based stationary phase(DPZ)was prepared by modifying zirconia with dodecylamine-N,N-dimethylenephosphonic acid(DDPA).DDPA was adsorbed on zirconia with only one phosphonic group,with the other being free.Besides the hydrophobic interaction provided by nonpolar dodecyl,DPZ also has dipolar interaction,ion-exchange or electrostatic repellent interaction provided by the free phosphonic group and amino group at different conditions.Separation of bases on this stationary phase was achieved with satisfaction owing to the various retention mechanisms.The influence of methanol content,pH value,ion types,and ionic strength of mobile phase are studied in detail.

  16. Electron transport in dodecylamine capped gold nanocluster films using current sensing atomic force microscope (C-AFM).

    Science.gov (United States)

    Chaudhary, Minakshi; Dey, Shirshendu; Date, Kalyani; Iyyer, S B; Dharmadhikaril, C V

    2009-09-01

    Electron transport across cataphoretically deposited dodecylamine capped gold nanocluster rough films on Si(111) substrate is investigated using current sensing atomic force microscopy. Contact mode images depict uniform deposition of agglomerates of gold nanoparticles. The current images display strong correlation with topographic images. The I-V measurement on a single agglomerate of approximately = 250 nm size at different forces exhibits force dependent threshold voltage. The electron transport from tip to sample is found to be ohmic in contrast to that from sample to tip which, exhibits Fowler-Nordheim behavior up to 35 nN force. At higher forces, the I-V behavior could be attributed to other electron transfer processes such as Schottky/Poole-Frenkel or trapping/detrapping, although no exact mechanism could be identified. The results are discussed in the light of models based on Coulomb blockaded collective charge transport in nanoparticle arrays duly accounting for the potential role of the capping layer.

  17. Characterization of bacterial spore germination using integrated phase contrast microscopy, Raman spectroscopy, and optical tweezers.

    Science.gov (United States)

    Kong, Lingbo; Zhang, Pengfei; Setlow, Peter; Li, Yong-Qing

    2010-05-01

    We present a methodology that combines external phase contrast microscopy, Raman spectroscopy, and optical tweezers to monitor a variety of changes during the germination of single Bacillus cereus spores in both nutrient (l-alanine) and non-nutrient (Ca-dipicolinic acid (DPA)) germinants with a temporal resolution of approximately 2 s. Phase contrast microscopy assesses changes in refractility of individual spores during germination, while Raman spectroscopy gives information on changes in spore-specific molecules. The results obtained include (1) the brightness of the phase contrast image of an individual dormant spore is proportional to the level of CaDPA in that spore; (2) the end of the first Stage of germination, revealed as the end of the rapid drop in spore refractility by phase contrast microscopy, precisely corresponds to the completion of the release of CaDPA as revealed by Raman spectroscopy; and (3) the correspondence between the rapid drop in spore refractility and complete CaDPA release was observed not only for spores germinating in the well-controlled environment of an optical trap but also for spores germinating when adhered on a microscope coverslip. Using this latter method, we also simultaneously characterized the distribution of the time-to-complete-CaDPA release (T(release)) of hundreds of individual B. cereus spores germinating with both saturating and subsaturating concentrations of l-alanine and with CaDPA.

  18. Photonic sintering of thin film prepared by dodecylamine capped CuIn{sub x}Ga{sub 1−x}Se{sub 2} nanoparticles for printed photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Manjeet, E-mail: msitbhu@gmail.com; Jiu, Jinting; Sugahara, Tohru; Suganuma, Katsuaki

    2014-08-28

    In this paper, we report solution phase large scale synthesis of monodisperse phase pure CuIn{sub x}Ga{sub 1−x}Se{sub 2} (CIGS) nanoparticles by using dodecylamine as solvent and dispersant. Various compositions of CIGS nanoparticles with different Ga content are synthesized by simply adding different amounts of Ga precursors. The band gap of CIGS nanoparticles can be tuned by changing Ga content. Effort is given to understand the formation pathway of CIGS phase so as to make the synthesis easier for the desired product. High intensity pulsed light technique, which provides extreme local heating, is used to sinter the thin film prepared using these nanoparticles on a Mo–glass surface. A uniformly conductive and dense CIGS film can be prepared by adjusting the energy of light and exposure time. The high intensity light irradiation of the CIGS film leads to diffusion of smaller CIGS nanoparticles to form a particle with larger grain size and thus enables sintering of particles without using high temperature processing. - Highlights: • Large scale synthesis of CuIn{sub x}Ga{sub 1−x}Se{sub 2} (CIGS) is reported. • Dodecylamine is used as surfactant and solvent. • CIGS phase formation mechanism is described. • High intensity pulsed light technique is used to sinter the CIGS film.

  19. Seed germination and vigor.

    Science.gov (United States)

    Rajjou, Loïc; Duval, Manuel; Gallardo, Karine; Catusse, Julie; Bally, Julia; Job, Claudette; Job, Dominique

    2012-01-01

    Germination vigor is driven by the ability of the plant embryo, embedded within the seed, to resume its metabolic activity in a coordinated and sequential manner. Studies using "-omics" approaches support the finding that a main contributor of seed germination success is the quality of the messenger RNAs stored during embryo maturation on the mother plant. In addition, proteostasis and DNA integrity play a major role in the germination phenotype. Because of its pivotal role in cell metabolism and its close relationships with hormone signaling pathways regulating seed germination, the sulfur amino acid metabolism pathway represents a key biochemical determinant of the commitment of the seed to initiate its development toward germination. This review highlights that germination vigor depends on multiple biochemical and molecular variables. Their characterization is expected to deliver new markers of seed quality that can be used in breeding programs and/or in biotechnological approaches to improve crop yields.

  20. Lattice potential energy and standard molar enthalpy in the formation of 1-dodecylamine hydrobromide(1-C12H25NH3·Br)(s)

    Institute of Scientific and Technical Information of China (English)

    Liu Yu-Pu; Di You-Ying; Dan Wen-Yan; He Dong-Hua; Kong Yu-Xia; Yang Wei-Wei

    2011-01-01

    This paper reports that 1-dodecylamine hydrobromide (1-C12H25NH3·Br)(s) has been synthesized using the liquid phase reaction method. The lattice potential energy of the compound 1-C12H25NH3·Br and the ionic volume and radius of the 1-C12H25NH3+ cation are obtained from the crystallographic data and other auxiliary ther-modynamic data. The constant-volume energy of combustion of 1-C12H25NH3·Br(s) is measured to be △cUm°(1-C12H25NH3·Br, s) =-(7369.03±3.28) kJ·mol-1 by means of an RBC-Ⅱ precision rotating-bomb combustion calorimeter at T=(298.15±0.001) K. The standard molar enthalpy of combustion of the compound is derived to be △cHm°(1-C12H25NH3·Br, s)=-(7384.52±3.28) kJ·mol-1 from the constant-volume energy of combustion. The standard molar enthalpy of formation of the compound is calculated to be △fHm°(1-C12H25NH3·Br, s)=-(1317.86±3.67) kJ·mol-1 from the standard molar enthalpy of combustion of the title compound and other auxiliary thermodynamic quantities through a thermochemical cycle.

  1. Biochemical Changes Associated with Germinating Rice Grains and Germination Improvement

    Institute of Scientific and Technical Information of China (English)

    Subajiny VELUPPILLAI; Ketheeswary NITHYANANTHARAJAH; Seevaratnam VASANTHARUBA; Sandrasegarampillai BALAKUMAR; Vasanthy ARASARATNAM

    2009-01-01

    To determine biochemical changes during the germination of rice grains (Oryza sativa L. subsp. indica var. Mottaikaruppan) and to improve germination rate using gibberellic acid and surfactants [sodium dodecyl sulfate (SDS) (1.0 g/L) and Triton-X-100 (1.0 mL/L)], whole rice grains soaked in distilled water for 12 h at 30oC were germinated in the dark at 30oC for five days. The highest germination rate (77.1%) was obtained on the 5th day. An increase in the content of reducing sugars from 7.3 to 58.1 mg/g DM (dry matter) was observed from the 1st day of germination. Free amino acids and soluble protein contents increased to 3.69 and 5.29 mg/g DM, respectively on the 5th day of germination. Total protein content decreased from 100.5 to 91.0 g/kg DM during germination. Increases in amylolytic (1.1 to 190.0 U/g DM) and proteolytic (0 to 0.12 U/g DM) activities were observed during germination. Effects of different concentrations of gibberellic acid on the germination of rice grains were evaluated and 0.1 g/L was found to promote germination. When effects of gibberellic acid (0.1 g/L) and surfactants were evaluated individually and together, higher germination rate was observed in the control experiment (grains germinated in distilled water), whereas giberellic acid and surfactants decreased the germination rate. Therefore, the flour obtained from the grains germinated for four days using distilled water to obtain high content of soluble materials and enzyme activities can be used in preparation of bakery items.

  2. Germination and storage of pollen

    NARCIS (Netherlands)

    Visser, T.

    1955-01-01

    Germination of pear pollen markedly improved when boric acid was added to the medium. The pollen was more sensitive to boron in water than in 10 % sugar solution. Supplying weak solutions of boron to pear branches before flowering resulted in a good germination of the pollen in sugar solution withou

  3. The generation of germinal centers

    NARCIS (Netherlands)

    Kroese, Fransciscus Gerardus Maria

    1987-01-01

    Germinal centers are clusters of B lymphoblastoid cells that develop after antigenic stimulation in follicles of peripheral lymphoid organs. These structures are thought to play a major role in the generation of B memory cells. This thesis is dealing with several aspects of these germinal centers. I

  4. Portable Diagnostics and Rapid Germination

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Zachary Spencer [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-12-01

    In the Bioenergy and Defense Department of Sandia National Laboratories, characterization of the BaDx (Bacillus anthracis diagnostic cartridge) was performed and rapid germination chemistry was investigated. BaDx was tested with complex sample matrixes inoculated with Bacillus anthracis, and the trials proved that BaDx will detect Bacillus anthracis in a variety of the medium, such as dirt, serum, blood, milk, and horse fluids. The dimensions of the device were altered to accommodate an E. coli or Listeria lateral flow immunoassay, and using a laser printer, BaDx devices were manufactured to identify E. coli and Listeria. Initial testing with E. coli versions of BaDx indicate that the device will be viable as a portable diagnostic cartridge. The device would be more effective with faster bacteria germination; hence studies were performed the use of rapid germination chemistry. Trials with calcium dipicolinic acid displayed increased cell germination, as shown by control studies using a microplate reader. Upon lyophilization the rapid germination chemistry failed to change growth patterns, indicating that the calcium dipicolinic acid was not solubilized under the conditions tested. Although incompatible with the portable diagnostic device, the experiments proved that the rapid germination chemistry was effective in increasing cell germination.

  5. seed germination and seedlings growth

    African Journals Online (AJOL)

    STORAGESEVER

    2007-12-17

    Dec 17, 2007 ... African Journal of Biotechnology Vol. 6 (24), pp. 2792-2802 ... needed for rapid cell respiration during germination, however, abscisic ... PAGE) was carried out in a vertical slab gel apparatus as described by Laemmli (1970).

  6. Ethylene, seed germination, and epinasty.

    Science.gov (United States)

    Stewart, E R; Freebairn, H T

    1969-07-01

    Ethylene activity in lettuce seed (Lactuca satina) germination and tomato (Lycopersicon esculentum) petiole epinasty has been characterized by using heat to inhibit ethylene synthesis. This procedure enabled a separation of the production of ethylene from the effect of ethylene. Ethylene was required in tomato petioles to produce the epinastic response and auxin was found to be active in producing epinasty through a stimulation of ethylene synthesis with the resulting ethylene being responsible for the epinasty. In the same manner, it was shown that gibberellic acid stimulated ethylene synthesis in lettuce seeds. The ethylene produced then in turn stimulated the seeds to germinate. It was hypothesized that ethylene was the intermediate which caused epinasty or seed germination. Auxin and gibberellin primarily induced their response by stimulating ethylene production.

  7. Effect of cigarette smoke on seed germination.

    Science.gov (United States)

    Noble, R E

    2001-02-21

    The effect of cigarette smoke was studied on the germination of radish, kale, lettuce, amaranth, wheat, rice, barley and rye seeds. It was found that such smoke markedly retarded, in all cases, the rate of germination. Furthermore, cigarette smoke caused a retardation of the levels of certain enzymes (alpha-amylase or lysozyme) known to be significant in the germination of these seeds.

  8. Initiation of bacterial spore germination.

    Science.gov (United States)

    Vary, J C; Halvorson, H O

    1968-04-01

    To investigate the problem of initiation in bacterial spore germination, we isolated, from extracts of dormant spores of Bacillus cereus strain T and B. licheniformis, a protein that initiated spore germination when added to a suspension of heat-activated spores. The optimal conditions for initiatory activity of this protein (the initiator) were 30 C in 0.01 to 0.04 m NaCl and 0.01 m tris(hydroxymethyl)aminomethane (pH 8.5). The initiator was inhibited by phosphate but required two co-factors, l-alanine (1/7 of K(m) for l-alanine-inhibited germination) and nicotinamide adenine dinucleotide (1.25 x 10(-4)m). In the crude extract, the initiator activity was increased 3.5-fold by heating the extract at 65 C for 10 min, but the partially purified initiator preparation was completely heat-sensitive (65 C for 5 min). Heat stability could be conferred on the purified initiator by adding 10(-3)m dipicolinic acid. A fractionation of this protein that excluded l-alanine dehydrogenase and adenosine deaminase from the initiator activity was developed. The molecular weight of the initiator was estimated as 7 x 10(4). The kinetics of germination in the presence of initiator were examined at various concentrations of l-alanine and nicotinamide adenine dinucleotide.

  9. Neonatal disorders of germinal matrix

    NARCIS (Netherlands)

    Raets, M M A; Dudink, J; Govaert, P

    2015-01-01

    The germinal matrix (GM) is a richly vascularized, transient layer near the ventricles. It produces neurons and glial cells, and is present in the foetal brain between 8 and 36 weeks of gestation. At 25 weeks, it reaches its maximum volume and subsequently withers. The GM is vulnerable to haemorrhag

  10. Habitat specialization through germination cueing

    DEFF Research Database (Denmark)

    Ten Brink, Dirk-Jan; Hendriksma, Harmen; Bruun, Hans Henrik

    2013-01-01

    This study examined the adaptive association between seed germination ecology and specialization to either forest or open habitats across a range of evolutionary lineages of seed plants, in order to test the hypotheses that (1) species' specialization to open vs. shaded habitats is consistently...

  11. Germination Requirements of Bacillus macerans Spores

    Science.gov (United States)

    Sacks, L. E.; Thompson, P. A.

    1971-01-01

    2-Phenylacetamide is an effective germinant for spores of five strains of Bacillus macerans, particularly in the presence of fructose. Benzyl penicillin, the phenyl acetamide derivative of penicillin, and phenylacetic acid are also good germinants. l-Asparagine is an excellent germinant for four strains. α-Amino-butyric acid is moderately effective. Pyridoxine, pyridoxal, adenine, and 2,6-diaminopurine are potent germinants for NCA strain 7X1 only. d-Glucose is a powerful germinant for strain B-70 only. d-Fructose and d-ribose strongly potentiate germination induced by other germinants (except l-asparagine) but have only weak activity by themselves. Niacinamide and nicotinamide-adenine dinucleotide, inactive by themselves, are active in the presence of fructose or ribose. Effects of pH, ion concentration, and temperature are described. PMID:4251279

  12. Effects of priming on seed germination and germination

    Directory of Open Access Journals (Sweden)

    azade hoseiny

    2009-06-01

    Full Text Available Four osmotica (water, hydrochloric acid (HCl 0.5 N, (HCl 0.1 N, sodium chloride 1.5 N and polyethylene glycol-6000 (PEG 6000 were used for priming of four varieties of sugar beet (Beta vulgaris namely KWS, Universe, Afshari and Orbise. The type of experiment was Factorial on the basis of completely randomized design with three replications. Fifthy seeds were washed by distilled water, HCl, PEG 6000 and NaCl and then each of the above treatments were applied for two hours. The most promising treatments in terms of the rate and percentage of germination were water and HCl. Radicle and coleoptil lengths were shorter in NaCl and PEG is comparison with HCl and water. Varieties of KWS, Universe and Orbice had longer shoots that shows the restage of them was more than other varieties and the treatment of HCl increased the percentage and rate of germination.

  13. Factors influencing seed germination in Cerrado grasses

    Directory of Open Access Journals (Sweden)

    Rosana Marta Kolb

    2016-03-01

    Full Text Available Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i recently collected seeds and seeds after six months storage, ii under constant and alternating temperatures, and iii in the presence and absence of light. Germinability, mean germination time (MGT and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most species, germinability and MGT were not altered by seed storage. Germination percentages were higher at alternating temperatures and in the presence of light, factors that are more similar to natural environmental situations compared with constant temperature or the absence of light. Our findings indicate that alternating temperatures and light incidence are key factors for germination of species of Poaceae. The maintenance of these environmental factors, which are crucial for the conservation of Cerrado grasslands, depends on appropriate management interventions, such as fire management and the control of biological invasion.

  14. Effect of industrial pollution on seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M.Z.; Qadir, S.A.

    1973-01-01

    The germination behavior of seeds in polluted waters and polluted soil extracts was found to be identical, only a few species behaved differently. Prosopis juliflora, Haloxylon recurvum, Acacia senegal showed best germination in the two conditions but Prosopis juliflora was the most resistant to pollution. In Suaeda fruticosa no germination took place in the control treatment whereas highest germination (70%) was seen in treatment with polluted soil extract of EPLA. Blepharis sindica showed a stimulating effect of polluted water on germination, whereas low germination was observed when their seeds were treated with the soil extract of the same site. 40% germination of Suaeda monoica was seen in polluted water of Carbon and Ribbon Mfg. Co., whereas 30% germination was found in a control treatment. Low percentage of germination was found when the seeds of Cassia holosericea were treated with polluted waters of different industries as compared to soil extract treatments of the same industries. Datura alba showed 50, 30 and 10% seed germination in polluted soil extract of Carbon and Ribbon Mfg. Co., in control and in polluted water of Darbar Soap Works, respectively. 5 references, 1 table.

  15. Proteomics of Rice Seed Germination

    Institute of Scientific and Technical Information of China (English)

    Dongli He; Chao Han; Xiaojian Yin; Hui Zhang; Pingfang Yang

    2012-01-01

    Seed germination is a complex physiological which starts from the uptake of water by the dry seeds and ends at the protrusion of the radicle.In order to elucidate the mechanism of rice seed germination,we have conducted a systematic proteomic analyses combining with 1-D via LC MS/MS,comparative 2-DE and iTRAQ techniques using the whole seed or dissected embryos and endosperm.During rice seed germination,the embryo and endosperm played different roles.The seed weight increased and complied by a triphasic model.Phase I accompanied with rapid seed water-up-take,the embryo produced gibberellic acid (GA) and diffused to aleurone and then prepared to initiate a signaling cascade to drive the reserves degradation in the starchy endosperm.Phase II is the most important stage for metabolic reactions reactivation,the reserves mobilization,cell construction respiration,cell wall loosening and coleoptile elongation,most of the metabolism related proteins sorted to different pathways were identified at 24 h after imbibition,but the metabolism of nucleotides was not active at this stage for few related proteins have been involved.The degradation of seed maturation and desiccation-associated proteins seemed to be earlier than that of the storage proteins and starch.The glycolysis was the main pathway for energy and substance providing.Phase III is another rapid water-uptake stage accompanying with TCA and aerobic respiration strengthening,cell division initiation and the radical protrusion.Interesting,both biosynthesis and degradation of the same macromolecule were concurrence even in the dry seed,which implied the sequentially matabolic and regulatory events triggered by water uptake during rice seed germination have been programmed during seed maturation.

  16. The biomechanics of seed germination.

    Science.gov (United States)

    Steinbrecher, Tina; Leubner-Metzger, Gerhard

    2016-12-07

    From a biomechanical perspective, the completion of seed (and fruit) germination depends on the balance of two opposing forces: the growth potential of the embryonic axis (radicle-hypocotyl growth zone) and the restraint of the seed-covering layers (endosperm, testa, and pericarp). The diverse seed tissues are composite materials which differ in their dynamic properties based on their distinct cell wall composition and water uptake capacities. The biomechanics of embryo cell growth during seed germination depend on irreversible cell wall loosening followed by water uptake due to the decreasing turgor, and this leads to embryo elongation and eventually radicle emergence. Endosperm weakening as a prerequisite for radicle emergence is a widespread phenomenon among angiosperms. Research into the biochemistry and biomechanics of endosperm weakening has demonstrated that the reduction in puncture force of a seed's micropylar endosperm is environmentally and hormonally regulated and involves tissue-specific expression of cell wall remodelling proteins such as expansins, diverse hydrolases, and the production of directly acting apoplastic reactive oxygen. The endosperm-weakening biomechanics and its underlying cell wall biochemistry differ between the micropylar (ME) and chalazal (CE) endosperm domains. In the ME, they involve cell wall loosening, cell separation, and programmed cell death to provide decreased and localized ME tissue resistance, autolysis, and finally the formation of an ME hole required for radicle emergence. Future work will further unravel the molecular mechanisms, environmental regulation, and evolution of the diverse biomechanical cell wall changes underpinning the control of germination by endosperm weakening.

  17. Recent advances in germination of Clostridium spores.

    Science.gov (United States)

    Olguín-Araneda, Valeria; Banawas, Saeed; Sarker, Mahfuzur R; Paredes-Sabja, Daniel

    2015-05-01

    Members of Clostridium genus are a diverse group of anaerobic spore-formers that includes several pathogenic species. Their anaerobic requirement enhances the importance of the dormant spore morphotype during infection, persistence and transmission. Bacterial spores are metabolically inactive and may survive for long times in the environment and germinate in presence of nutrients termed germinants. Recent progress with spores of several Clostridium species has identified the germinant receptors (GRs) involved in nutrient germinant recognition and initiation of spore germination. Signal transduction from GRs to the downstream effectors remains poorly understood but involves the release of dipicolinic acid. Two mechanistically different cortex hydrolytic machineries are present in Clostridium spores. Recent studies have also shed light into novel biological events that occur during spore formation (accumulation of transcriptional units) and transcription during early spore outgrowth. In summary, this review will cover all of the recent advances in Clostridium spore germination. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  18. Detecting Cortex Fragments During Bacterial Spore Germination.

    Science.gov (United States)

    Francis, Michael B; Sorg, Joseph A

    2016-06-25

    The process of endospore germination in Clostridium difficile, and other Clostridia, increasingly is being found to differ from the model spore-forming bacterium, Bacillus subtilis. Germination is triggered by small molecule germinants and occurs without the need for macromolecular synthesis. Though differences exist between the mechanisms of spore germination in species of Bacillus and Clostridium, a common requirement is the hydrolysis of the peptidoglycan-like cortex which allows the spore core to swell and rehydrate. After rehydration, metabolism can begin and this, eventually, leads to outgrowth of a vegetative cell. The detection of hydrolyzed cortex fragments during spore germination can be difficult and the modifications to the previously described assays can be confusing or difficult to reproduce. Thus, based on our recent report using this assay, we detail a step-by-step protocol for the colorimetric detection of cortex fragments during bacterial spore germination.

  19. Germination of Bacillus anthracis spores:research advances%炭疽芽孢杆菌芽孢萌发研究进展

    Institute of Scientific and Technical Information of China (English)

    高志奇; 刘先凯; 王恒樑

    2014-01-01

    芽孢是炭疽芽孢杆菌为应对不适的外界环境而形成的一种生命形式,休眠期的芽孢可以通过萌发恢复生长成为繁殖体。萌发过程作为关键步骤,可以由营养萌发剂和一些非营养类物质或者在其他情况下触发。在萌发过程中,萌发剂通过与存在于芽孢内膜上的萌发剂受体结合来触发芽孢核内各种阳离子的释放以及芽孢核对水的吸收。在芽孢皮层的肽聚糖被酶水解后,芽孢核逐渐完全水合化,开始进行新陈代谢以及大分子的合成活动,逐渐成长为一个新的营养细胞。该文将从萌发受体、芽孢皮层水解酶功能等方面对炭疽菌芽孢萌发机制进行阐述。%A spore is another life cycle form of Bacillus anthracis for resisting starvation.When conditions are favorable for growth, the dormant spore will germinate,go through outgrowth, and are ultimately converted back into a growing cell. As the first step back to vegetative growth, germination could be induced by nutrients and a variety of non-nutrient agents. Nutrient germinants trigger cation release and water absorption by binding to receptors in the spore′s inner membrane.Then the spore′s peptidoglycan cortex is hydrolyzed and the spore core rehydrates, which allows the resumption of spore metabo-lism and macromolecular synthesis.This paper reviews the nutrient germinant receptor and cortex lytic enzymes in the spore germination process of B.anthracis.

  20. GERMINATION STUDIES ON Tabebuia impetiginosa Mart. SEEDS

    Directory of Open Access Journals (Sweden)

    Edvaldo Aparecido Amaral da Silva

    2004-06-01

    Full Text Available Seed germination and seedling production of native forest tree species are an important step in ex situ conservation programs and in the reforestation with ecological purposes. Therefore, understanding seed germination and its regulation is mandatory for the complete success of the conservation programs and revegetation techniques. Thus, morphological studies, temperature requirements for seed germination and its control by gibberellins (GAs were studied in Tabebuia impetiginosa (“ipê-roxo” seeds. The best temperature for germination under constant light was 30oC. The imbibition of T. impetiginosa seeds followed the common triphasic pattern, with most of the seeds attaining phase II at 24 hours and phase III at 72 hours of imbibition. Visible germination, as radicle elongation, started at 30 hours in water-imbibed seeds and at 24 hours in GA-imbibed seeds. Seeds imbibed in Paclobutrazol, an inhibitor of GA biosynthesis, failed to germinate. However, application of exogenous gibberellins overcame inhibition and allowed germination, suggesting that GAs are regulators of Tabebuia impetiginosa seed germination. The results suggested that germination in Tabebuia impetiginosa seeds is controlled by elongation of the radicle and gibberellins may play an important role in regulating it. The possible role of gibberellins is discussed.

  1. Identification of embryo proteins associated with seed germination and seedling establishment in germinating rice seeds.

    Science.gov (United States)

    Liu, Shu-Jun; Xu, Heng-Heng; Wang, Wei-Qing; Li, Ni; Wang, Wei-Ping; Lu, Zhuang; Møller, Ian Max; Song, Song-Quan

    2016-06-01

    Seed germination is a critical phase in the plant life cycle, but the mechanism of seed germination is still poorly understood. In the present study, rice (Oryza sativa L. cv. Peiai 64S) seeds were sampled individually when they reached different germination stages, quiescent, germinated sensu stricto, germinated completely and seedling, and were used to study the changes in the embryo proteome. A total of 88 protein spots showed a significant change in abundance during germination in water, and the results showed an activation of metabolic processes. Cell division, cell wall synthesis, and secondary metabolism were activated at late seed germination and during preparation for subsequent seedling establishment. Cycloheximide (CHX) at 70μM inhibited seedling establishment without an apparent negative effect on seed germination, while CHX at 500μM completely blocked seed germination. We used this observation to identify the potentially important proteins involved in seed germination (coleoptile protrusion) and seedling establishment (coleoptile and radicle protrusion). Twenty-six protein spots, mainly associated with sugar/polysaccharide metabolism and energy production, showed a significant difference in abundance during seed germination. Forty-nine protein spots, mainly involved in cell wall biosynthesis, proteolysis as well as cell defense and rescue, were required for seedling establishment. The results help improve our understanding of the key events (proteins) involved in germination and seedling development.

  2. Modelling the effect of temperature on seed germination in some ...

    African Journals Online (AJOL)

    USER

    2010-03-01

    Mar 1, 2010 ... The prediction of germination percentage (GP) and germination speed (GS) of the seeds for some ... rate and the germination frequency alongside the incu- ..... Considering that there has been marked interest by many.

  3. Germination Time Dependence of Bioactive Compounds and Antioxidant Activity in Germinated Rough Rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Anuchita Moongngarm

    2011-01-01

    Full Text Available Problem statement: Germinated rice has been recognized as a functional food and its health benefits. However, most related studies were on germinated brown rice but our previous study indicated that germination of rough rice was an effective method to obtain high concentrations of bioactive compounds. Germination time is one of the most important factors affecting the level of biochemical compositions and antioxidant activity. Approach: Rough rice seeds were soaked in water for 2 days and germinated for four different days (1- 4 days. Total phenolic compounds, phytic acid, á-tocopherol, á- tocopherol, á-tocotrienol and á-oryzanol were investigated compared with those of ungerminated brown rice. The antioxidant activity of germinated rice was evaluated through four different methods, the 1, 1- Diphenyl-2-Picrylhydrazyl (DPPH free radical scavenging assay, hydroxyl radical scavenging activity, lipid peroxidation assay and linoleic acid emulsion system-thiocyanate method. Results: The results showed that the germination for 2 days or longer, after soaking, yielded significantly higher level of total phenolic, á-tocopherol, á-tocopherol, á-tocotrienol and á-oryzanol than those of ungerminated brown rice and soaked rice, whilst the concentration of phytic acid was reduced significantly when germination time was increased. The samples germinated for one day or longer also revealed greater antioxidant activity than those of ungerminated rice. Conclusion: The level of bioactive compounds and antioxidant activity of germinated rough rice were affected by germination time. Germination for 2 and 3 days was the optimum time for germination rough rice to obtain high concentration of bioactive compounds and high antioxidant activity. The germination process of rough rice could be a potential method to obtain functional germinated rice flour with high bioactive compounds and health beneficial properties and could be applied to produce

  4. Neonatal disorders of germinal matrix.

    Science.gov (United States)

    Raets, M M A; Dudink, J; Govaert, P

    2015-11-01

    The germinal matrix (GM) is a richly vascularized, transient layer near the ventricles. It produces neurons and glial cells, and is present in the foetal brain between 8 and 36 weeks of gestation. At 25 weeks, it reaches its maximum volume and subsequently withers. The GM is vulnerable to haemorrhage in preterm infants. This selective vulnerability is explained by limited astrocyte end-feet coverage of microvessels, reduced expression of fibronectin and immature tight junctions. Focal lesions in the neonatal period include haemorrhage, germinolysis and stroke. Such lesions in transient layers interrupt normal brain maturation and induce neurodevelopmental sequelae.

  5. QTL analysis of rice low temperature germinability

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A double haploid population, derived from anther culture of F1 hybrid between a typical indica and a japonica (ZYQ8/JX17), has been used to investigate the low temperature germinability (LTG) at 15C. The low temperature germinability of two parents was significantly different.In 6-11 d, the germination percentage of ZYQ8 was higher than that of JX17. In 12-16 d, the germination percentage of JX17 was higher than that of ZYQ8. The quantitative trait loci (QTLs) of every day for low temperature germinability have been mapped based on a molecular linkage map constructed from this population. In 8-11 d, qLTG-9 was identiffed in C397B-RZ617B on chromosome 9, the additive effect was positive, showing that the allele from JX17 could increase low temperature germinability. In 12-16 d, qLTG4 was mapped between RG908 and CT563 on chromosome 4,the additive effect was negative, showing that the allele from ZYQ8 could increase low temperature germinability. These two QTLs were detected at different stages, showing the complexity of the mechanism of iow temperature germinability.

  6. Seed germination behavior of swallow wort

    Directory of Open Access Journals (Sweden)

    amir hosein pahlavani

    2009-06-01

    Full Text Available The exotic plant, Swallow- wort, a twining perennial of the Milkweed family, has become increasingly invasive in some place of Iran, especially orchards. Increased knowledge of wort germination biology would facilitate development of an optimum control program. Germination of Swallow wort seeds as affected by environmental factors was studied under controlled-environment growth chamber conditions. The following studies were conducted in plant Pests & Diseases Research Institute during the years 2003-4: 1- Effect of constant temperature on germination that including 10, 15, 18, 20, 25, 30, 35 and 40˚C; 2- Effect of light on constant germination; 3- Effect of temperature fluctuations on seed germination: 15/7, 20/12, 25/17 and 30/22˚C. All experiments were conducted with 8 replications. Swallow wort seeds showed no dormancy when detachment from mother plant. Seed germination was strongly influenced by temperature. Light did not play a crucial role on seed germination of this weed. Therefore Swallow wort seeds were not photoblastic and temperature fluctuations did not increase seed germination of Swallow wort. The above characteristics are very important in making swallowwort an invasive weed. Having precise information of these traits enables us to a better management and control of this troublesome weed.

  7. [Metabolic control of seed germination].

    Science.gov (United States)

    Catusse, Julie; Strub, Jean-Marc; Job, Claudette; Van Dorsselaer, Alain; Job, Dominique

    2008-01-01

    We have used proteomics to better characterize germination and early seedling vigor in sugarbeet. Our strategy includes (1) construction of proteome reference maps for dry and germinating seeds of a high-vigor reference seed lot; (2) investigation of the specific tissue accumulation of proteins (root, cotyledon, perisperm); (3) investigation of changes in protein expression profiles detected in the reference seed lot subjected to different vigor-modifying treatments, e.g. aging and/or priming. More than 1 000 sugarbeet seed proteins have been identified by LC/MS-MS mass spectrometry (albumins, globulins and glutelins have been analyzed separately). Due to the conservation of protein sequences and the quality of MS sequencing (more than 10 000 peptide sequences have been obtained), the success rate of protein identification was on the average of 80%. This is to our knowledge the best detailed proteome analysis ever carried out in seeds. The data allowed us to build a detailed metabolic chart of the sugarbeet seed, generating new insights into the molecular mechanisms determining the development of a new seedling. Also, the proteome of a seed-storage tissue as the perisperm is described for the first time.

  8. Maximizing seed germination in two Acacia species

    Institute of Scientific and Technical Information of China (English)

    Akram Kiani Abari; Mohammad Hoseini Nasr; Mohammad Hodjati; Dariush Bayat; Morteza Radmehr

    2012-01-01

    Revegetation of disturbed land,particularly in arid environment,is often hindered by low seedling establishment.Information on seed biology and germination cues of valuable species is lacking.We investigated seed germination of two Acacia species (Acacia tortilis (Forsk.) Hayne and Acacia oerfota (Forssk) schweinf),required for nitrogen fixation and rehabilitation of arid and semi-arid areas.(four pre-germination seed treatments were applied in order to find the best treatment in germinating acacia species.The medium was L2 and three replicates were used.Seeds pre-treated with sand paper and also with H2SO4 and then H2O2 had the highest germination percentage in both species.The lowest germination percentage resulted from soaking seeds in water for 48 h followed by soaking in H2SO4 for A.oerfota and from soaking in water for 24 h for A.tortilis.Because the use of sand paper is difficult and time consuming,we recommend pre-treatment of A.tortilis and A.oerfota seeds with H2SO4 and H2O2 before planting.Our study results are significant for conservation agencies with an interest in optimizing germination in arid zones for rehabilitation and reforestation.

  9. Spontaneous germinal centers and autoimmunity.

    Science.gov (United States)

    Domeier, Phillip P; Schell, Stephanie L; Rahman, Ziaur S M

    2017-02-01

    Germinal centers (GCs) are dynamic microenvironments that form in the secondary lymphoid organs and generate somatically mutated high-affinity antibodies necessary to establish an effective humoral immune response. Tight regulation of GC responses is critical for maintaining self-tolerance. GCs can arise in the absence of purposeful immunization or overt infection (called spontaneous GCs, Spt-GCs). In autoimmune-prone mice and patients with autoimmune disease, aberrant regulation of Spt-GCs is thought to promote the development of somatically mutated pathogenic autoantibodies and the subsequent development of autoimmunity. The mechanisms that control the formation of Spt-GCs and promote systemic autoimmune diseases remain an open question and the focus of ongoing studies. Here, we discuss the most current studies on the role of Spt-GCs in autoimmunity.

  10. Photocontrol of germination in Amaranthus caudatus.

    Science.gov (United States)

    Kendrick, R E; Frankland, B

    1969-12-01

    Germination of Amaranthus caudatus is inhibited by light, far-red being the most effective part of the spectrum. At temperatures of 25° and below there is a low final germination percentage under continuous far-red whereas above 25° there is only a delaying effect. In the presence of a saturating concentration of gibberellic acid (GA3) at 25° seeds germinate under continuous far-red although they are delayed. At 25° seeds exposed to 48 hr far-red fail to germinate when transferred to darkness. This induced dormancy can be broken by a single short exposure to red light given at any time after the far-red illumination. This effect of short red can be reversed by a subsequent short period of far-red indicating that the seeds are phytochrome controlled. Although most seeds have escaped from the reversing effect of short far-red after an intervening dark period of 5 hours, germination is greatly reduced by continuous far-red at this time. Results of exposing seeds to varying periods of far-red before and after dark imbibition are interpreted in terms of a continual production of phytochrome in its active P fr form and a requirement for P fr action over a long period of time. Effects of intermittent and continuous low intensity far-red on the inhibition of germination provides further evidence for a low energy photoreaction involving phytochrome. Effects on Germination Index of continuous illumination with various light sources maintaining different P fr /P total ratios have been investigated. The results suggest that the proportion of phytochrome in the P fr form is the most important factor in the regulation of germination. A scheme for the phytochrome control of germination in Amaranthus caudatus is presented and possible explanations for the dependence on P fr /P total ratio are discussed.

  11. 7 CFR 201.54 - Number of seeds for germination.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Number of seeds for germination. 201.54 Section 201.54... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of...

  12. Pulling the trigger: the mechanism of bacterial spore germination.

    Science.gov (United States)

    Foster, S J; Johnstone, K

    1990-01-01

    In spite of displaying the most extreme dormancy and resistance properties known among living systems, bacterial endospores retain an alert environment-sensing mechanism that can respond within seconds to the presence of specific germinants. This germination response is triggered in the absence of both germinant and germinant-stimulated metabolism. Genes coding for components of the sensing mechanism in spores of Bacillus subtilis have been cloned and sequenced. However, the molecular mechanism whereby these receptors interact with germinants to initiate the germination response is unknown. Recent evidence has suggested that in spores of Bacillus megaterium KM, proteolytic activation of an autolytic enzyme constitutes part of the germination trigger reaction.

  13. Phytochrome and Seed Germination. I. Temperature Dependence and Relative P(FR) Levels in the Germination of Dark-germinating Tomato Seeds.

    Science.gov (United States)

    Mancinelli, A L; Yaniv, Z; Smith, P

    1967-03-01

    Germination of the dark-germinating seeds of 3 varieties of tomato is controlled by the phytochrome system. Germination is inhibited by far red radiation and repromoted by red applied after far red. At low temperatures, 17 to 20 degrees , a single, low energy far red irradiation is sufficient to inhibit germination in all 3 varieties. At higher temperatures far red is less effective in the inhibition of the germination of the tomato seeds. The phytochrome fraction present as P(FR) in the dark-germinating seeds of the Ace variety is about 40% of the total phytochrome present.

  14. Spore germination and germinant receptor genes in wild strains of Bacillus subtilis.

    Science.gov (United States)

    Alzahrani, O M; Moir, A

    2014-09-01

    To compare the germination of laboratory and wild strains of Bacillus subtilis. The spore germination of B. subtilis 168 (subsp. subtilis) was compared with that of the laboratory strain W23 (subsp. spizizenii) and desert-sourced isolates, including one member of subsp. subtilis (RO-NN-1), strains TU-B-10, RO-E-2, N10 and DV1-B-1, (all subsp. spizizenii), the B. mojavensis strain RO-H-1 and a B. subtilis natto strain. All germinated in L-alanine, although some were slower, and some 10-fold less sensitive to germinant. All germinated in calcium dipicolinate (CaDPA). Germination in asparagine, glucose, fructose + KCl was slow and incomplete in many of the strains, and decoating RO-NN-1 and W23 spores did not restore germination rates. Comparing the sequences of B. subtilis strains 168, RO-NN-1, W23, TU-B-10 and DV1-B-1, the operons encoding GerA, B and K germinant receptors were intact, although the two additional operons yndDEF and yfkQRST had suffered deletions or were absent in several spizizenii strains. Wild strains possess an efficient germination machinery for L-alanine germination. AGFK germination is often less efficient, the gerB genes more diverged, and the two germinant receptor operons of unknown function have been lost from the genome in many subsp. spizizenii strains. The two major subspecies of B. subtilis have conserved GerA receptor function, confirming its importance, at least in the natural environments of these strains. © 2014 The Society for Applied Microbiology.

  15. Workshop report: modeling the molecular mechanism of bacterial spore germination and elucidating reasons for germination heterogeneity.

    Science.gov (United States)

    Indest, Karl J; Buchholz, Wallace G; Faeder, Jim R; Setlow, Peter

    2009-08-01

    Over the course of 2 days, top researchers in the fields of bacterial spore biology and computational biology discussed approaches to determine the cause of spore germination heterogeneity. Biological and mathematical data gaps were identified, and experimental approaches and computational strategies for modeling spore germination were presented and evaluated. As a result of these interactions, future research directions were defined, the outcome of which should result in a robust model to help define the molecular mechanism(s) of spore germination. Mechanistic understanding of germination will be instrumental for developing novel sterilization, treatment, and decontamination strategies to mitigate threats posed by spores.

  16. Bioethanol production from germinated grain by inherent enzymes

    OpenAIRE

    Kádár, Zsófia; Christensen, Anne Deen; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2009-01-01

    The malting in brewing process develops enzymes that are required to hydrolyze the complex starch in grain into simple fermentable sugars. These proceed the three following steps: Steeping encourages germination to start, germination prepares the conversion of the starch to sugars, and kilning stops the germination. In this study, a method for bioethanol production from rye grain was developed by utilizing the inherent amylase activity from germination of the seed. Grain germination was pe...

  17. Bacterial spore germination and protein mobility.

    Science.gov (United States)

    Moir, Anne

    2003-10-01

    Fluorescence recovery after photobleaching (FRAP) of green fluorescent protein (GFP) has been used to report on protein mobility in single spores. Proteins found in dormant Bacillus spores are not mobile; however, mobility is restored when germination occurs and the core rehydrates. Spores of a cwlD mutant, in which the cortex is resistant to hydrolysis, are able to complete the earliest stages of germination in response to a specific germinant stimulus; in these circumstances, the protein in the spore remains immobile. Therefore, the earliest stages of spore germination, including loss of resistance to extreme heat and the complete release of the spore component dipicolinic acid, are achieved without the restoration of protein mobility.

  18. Germination, growth and physiological responses of Senegalia ...

    African Journals Online (AJOL)

    Dioumacor FALL

    2016-09-14

    Sep 14, 2016 ... photosynthesis such as enzymes, chlorophylls, and carotenoids are also .... The reverse transcription (RT) reactions were performed at 42°C for ..... light on germination of invasive Prosopis juliflora (Sw.) D.C. J. Arid. Environ.

  19. (edta) on the germination of tomato

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    has been found to reduced salinity stress on germination of two species of pepper .... osmotic component, with the ionic component, involving accumulation of Na and Cl .... Salt and drought stress signal transduction in plants. Annal Review of.

  20. Germination of Afrocarpus usambarensis and Podocarpus ...

    African Journals Online (AJOL)

    ACSS

    Uganda Journal of Agricultural Sciences by National Agricultural Research Organisation ..... Germination capacity of A. usambarensis and P. milanjianus seeds ..... properly managed to provide seeds. ... for the permission to carry out the study.

  1. Oxygen dependency of germinating Brassica seeds

    Science.gov (United States)

    Park, Myoung Ryoul; Hasenstein, Karl H.

    2016-02-01

    Establishing plants in space, Moon or Mars requires adaptation to altered conditions, including reduced pressure and composition of atmospheres. To determine the oxygen requirements for seed germination, we imbibed Brassica rapa seeds under varying oxygen concentrations and profiled the transcription patterns of genes related to early metabolism such as starch degradation, glycolysis, and fermentation. We also analyzed the activity of lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH), and measured starch degradation. Partial oxygen pressure (pO2) greater than 10% resulted in normal germination (i.e., protrusion of radicle about 18 hours after imbibition) but lower pO2 delayed and reduced germination. Imbibition in an oxygen-free atmosphere for three days resulted in no germination but subsequent transfer to air initiated germination in 75% of the seeds and the root growth rate was transiently greater than in roots germinated under ambient pO2. In hypoxic seeds soluble sugars degraded faster but the content of starch after 24 h was higher than at ambient oxygen. Transcription of genes related to starch degradation, α-amylase (AMY) and Sucrose Synthase (SUS), was higher under ambient O2 than under hypoxia. Glycolysis and fermentation pathway-related genes, glucose phosphate isomerase (GPI), 6-phosphofructokinase (PFK), fructose 1,6-bisphosphate aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate decarboxylase (PDC), LDH, and ADH, were induced by low pO2. The activity of LDH and ADH was the highest in anoxic seeds. Germination under low O2 conditions initiated ethanolic fermentation. Therefore, sufficient oxygen availability is important for germination before photosynthesis provides necessary oxygen and the determination of an oxygen carrying capacity is important for uniform growth in space conditions.

  2. Phospholipase Cδ regulates germination of Dictyostelium spores

    Directory of Open Access Journals (Sweden)

    Van Haastert Peter JM

    2001-12-01

    Full Text Available Abstract Background Many eukaryotes, including plants and fungi make spores that resist severe environmental stress. The micro-organism Dictyostelium contains a single phospholipase C gene (PLC; deletion of the gene has no effect on growth, cell movement and differentiation. In this report we show that PLC is essential to sense the environment of food-activated spores. Results Plc-null spores germinate at alkaline pH, reduced temperature or increased osmolarity, conditions at which the emerging amoebae can not grow. In contrast, food-activated wild-type spores return to dormancy till conditions in the environment allow growth. The analysis of inositol 1,4,5-trisphosphate (IP3 levels and the effect of added IP3 uncover an unexpected mechanism how PLC regulates spore germination: i deletion of PLC induces the enhanced activity of an IP5 phosphatase leading to high IP3 levels in plc-null cells; ii in wild-type spores unfavourable conditions inhibit PLC leading to a reduction of IP3 levels; addition of exogenous IP3 to wild-type spores induces germination at unfavourable conditions; iii in plc-null spores IP3 levels remain high, also at unfavourable environmental conditions. Conclusions The results imply that environmental conditions regulate PLC activity and that IP3 induces spore germination; the uncontrolled germination of plc-null spores is not due to a lack of PLC activity but to the constitutive activation of an alternative IP3-forming pathway.

  3. Combining Ability for Germination Traits in Jatropha curcas L.

    Directory of Open Access Journals (Sweden)

    A. K. M. Aminul Islam

    2013-01-01

    Full Text Available Six parents of Jatropha curcas were crossed in half diallel fashion, and the F1s were evaluated to determine the combining ability for nine germination parameters. The ratio between general combining ability (GCA and specific combining ability (SCA variances indicated preponderance of additive gene action for all the characters except germination percentage, time of 50% germination, seedling length, and seedling vigor index. The parents P1 and P2 were the best general combiner for most of the characters studied. The cross P1×P5 was the best specific combiner for speed of emergence, germination percentage, germination energy, germination index, and seedling vigor index, the cross P2×P5 for mean germination time, time of 50% germination, and seedling length, and the cross P4×P5 for number of days to first germination. The germination percentage varied from 58.06 to 92.76% among the parents and 53.43 to 98.96% among the hybrids. The highest germination (98.96% was observed in hybrid P2×P4, and none of the hybrids or parents showed 100% germination. The highest germination index (GI and seedling vigor index (SVI were found in hybrid P1×P5 and P2×P5, respectively. The results of this study provide clue for the improvement of Jatropha variety through breeding program.

  4. Combining ability for germination traits in Jatropha curcas L.

    Science.gov (United States)

    Islam, A K M Aminul; Anuar, Nurina; Yaakob, Zahira; Ghani, Jaharah A; Osman, Mohamad

    2013-01-01

    Six parents of Jatropha curcas were crossed in half diallel fashion, and the F 1s were evaluated to determine the combining ability for nine germination parameters. The ratio between general combining ability (GCA) and specific combining ability (SCA) variances indicated preponderance of additive gene action for all the characters except germination percentage, time of 50% germination, seedling length, and seedling vigor index. The parents P 1 and P 2 were the best general combiner for most of the characters studied. The cross P 1 × P 5 was the best specific combiner for speed of emergence, germination percentage, germination energy, germination index, and seedling vigor index, the cross P 2 × P 5 for mean germination time, time of 50% germination, and seedling length, and the cross P 4 × P 5 for number of days to first germination. The germination percentage varied from 58.06 to 92.76% among the parents and 53.43 to 98.96% among the hybrids. The highest germination (98.96%) was observed in hybrid P 2 × P 4, and none of the hybrids or parents showed 100% germination. The highest germination index (GI) and seedling vigor index (SVI) were found in hybrid P 1 × P 5 and P 2 × P 5, respectively. The results of this study provide clue for the improvement of Jatropha variety through breeding program.

  5. Germination of Croton urucurana L. seeds exposed to different storage temperatures and pre-germinative treatments.

    Science.gov (United States)

    Scalon, Silvana P Q; Mussury, Rosilda M; Lima, Andréa A

    2012-03-01

    The present work evaluated the germinability and vigor of Croton urucurana seeds. 1) Seeds were sorted by color (caramel, gray and black) and were subjected to seven different pre-germination treatments followed by incubation at 20ºC, 25°C or 20/30°C. 2) Seeds were stored in cold chambers or at room temperature for up to 300 days and were subsequently incubated at 20/30ºC in a germination chamber or under greenhouse conditions. Only gray seeds showed significant germination rates. The highest first count percentages of total germination and the highest germination speed indices were observed in control seeds and in those which were treated with water or 200 mg.L(-1) gibberellic acid for 12 hours. Seeds stored under refrigeration showed the highest values for all of the characteristics examined, as well as less electrical conductivity of the imbibing solution. Seedlings were more vigorous when seeds were stored for 300 days in a cold chamber. The seedlings production can be increased by incubating the seeds at alternating temperatures (20/30°C). The seeds do not need pre-germination treatments.

  6. Effect of chromium toxicity on germination and early seedling growth ...

    African Journals Online (AJOL)

    USER

    2010-07-19

    Jul 19, 2010 ... causing toxicity to plants as exhibited by reduced seed germination ... hypochlorite for 1 min to prevent fungal attack, and triple-rinsed in distilled ..... Effects of arsenic on seed germination and physiological activities of wheat.

  7. Thermogenetic curves and thermokinetics of seed germination of Robinia pseudoacaia

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Seed germination process has closely relation with material transformation and energy exchange within the seed. Study on its thermal effect is important for understanding the mechanism and the influencing factors of the seed germination. The thermogenetic curves of seed germination of Robinia pseudoacacia was measured by a new-type conductive microcalo-rimeter made in Wuhan University. The relationship was analyzed between the germination thermogenetic regulation and seed germination physiology. The thermogentic curves were further analyzed by thermokinetic theory to obtain the dynamic parameters and the thermokinetic model on seed germination of Robinia pseudoacacia. The relationship of the thermogenetic power(μw) and the germination time(h) of the germination process of 20 grains Robinia pseudocacia seeds at 25℃ was P=208.77/[0.1937+0.8063exp(-0.06563t)

  8. Measuring Total and Germinable Spore Populations

    Science.gov (United States)

    Noell, A.C.; Yung, P.T.; Yang, W.; Lee, C.; Ponce, A.

    2011-01-01

    It has been shown that bacterial endospores can be enumerated using a microscopy based assay that images the luminescent halos from terbium ions bound to dipicolinic acid, a spore specific chemical marker released upon spore germination. Further development of the instrument has simplified it towards automation while at the same time improving image quality. Enumeration of total spore populations has also been developed allowing measurement of the percentage of viable spores in any population by comparing the germinable/culturable spores to the total. Percentage viability will allow a more quantitative comparison of the ability of spores to survive across a wide range of extreme environments.

  9. Biochemical Changes During Seed Germination of Sterculia urens Roxb.

    OpenAIRE

    Botcha SATYANARAYANA; Prattipati Subhashini DEVI; Atluru ARUNDATHI

    2011-01-01

    The present study describes biochemical changes taking place during seed germination of Sterculia urens. The levels of proteins, total amino acids, reducing sugars, total soluble sugars and lipids were studied during various stages of seed germination (0-15 days). Total protein content was decreased in cotyledons during seed germination while free amino acid content increased to its maximum extent by 9th day of germination and reverse trend thereafter. The levels of reducing sugars and total ...

  10. Factors Defining Field Germination of Oilseed Radish Seeds

    Directory of Open Access Journals (Sweden)

    N.V. Dorofeev

    2013-08-01

    Full Text Available Influence of temperature, depth of crops and granulometric of soil structure on germination speed, laboratory and field germination of oilseed radish seeds were studied. It was established that the period of seed-germination is defined both by temperature and granulometric structure of soil. The highest field germination was marked on sandy loam at depth of crops' seeds at 3 cm and 20°С.

  11. Factors Defining Field Germination of Oilseed Radish Seeds

    OpenAIRE

    N.V. Dorofeev; E.V. Bojarkin; A.A. Peshkova

    2013-01-01

    Influence of temperature, depth of crops and granulometric of soil structure on germination speed, laboratory and field germination of oilseed radish seeds were studied. It was established that the period of seed-germination is defined both by temperature and granulometric structure of soil. The highest field germination was marked on sandy loam at depth of crops' seeds at 3 cm and 20°С.

  12. The pleiotropic effects of the seed germination inhibitor germostatin

    OpenAIRE

    Ye, Yajin; Zhao, Yang

    2016-01-01

    Seed dormancy and germination are the most important adaptive traits of seed plants, which control the germination in a proper space and time. Internal genetic factors together with environmental cues govern seed dormancy and germination. Abscisic acid (ABA), a key phytohormone induces seed dormancy and inhibits seed germination through its molecular genetic signaling network responding the seed inherent physiological and environmental factors. Recently, auxin has been shown to be another phy...

  13. Starch bioengineering affects cereal grain germination and seedling establishment

    DEFF Research Database (Denmark)

    Shaik, Shahnoor Sultana; Carciofi, Massimiliano; Martens, Helle Juel

    2014-01-01

    Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule...

  14. DOG1-imposed dormancy mediates germination responses to temperature cues

    NARCIS (Netherlands)

    Murphey, M.; Kovach, K.; Elnacash, T.; He, H.; Bentsink, L.; Donohue, K.

    2015-01-01

    Seed dormancy and environment-dependent germination requirements interact to determine the timing of germination in natural environments. This study tested the contribution of the dormancy gene Delay Of Germination 1 (DOG1) to primary and secondary dormancy induction in response to environmental

  15. Factors affecting the germination of hybrid rose achenes

    NARCIS (Netherlands)

    Vries, De D.P.; Dubois, L.A.M.

    2015-01-01

    The smooth germination of mature Hybrid rose achenes is hampered by (i) hardseededness (HS), (ii) primary dormancy (PD) and (iii) germination polymorphism (GP). HS is owing to the hard pericarp. PD is, in principle, a natural phenomenon that protects the seeds from precocious germination. For ger

  16. Effect of Natural Brassinolide on Germination of Ailanthus altissima Seeds

    Institute of Scientific and Technical Information of China (English)

    Li Kai-rong; Zhang Wei-bing; Li Hui-ke

    2005-01-01

    The germination capacity of Ailanthus altissima seeds improved after the seeds were soaked with different concentrations of natural brassinolide (NBR). The germination rate and germination energy of the seeds increased by 17.6% and 18.8%, and treatment, compared with the control. After hypocotyls ofA. altissima were treated with NBR, the elongation of the hypocotyls inA. altissima hypocotyls.

  17. Factors affecting the germination of hybrid rose achenes

    NARCIS (Netherlands)

    Vries, De D.P.; Dubois, L.A.M.

    2015-01-01

    The smooth germination of mature Hybrid rose achenes is hampered by (i) hardseededness (HS), (ii) primary dormancy (PD) and (iii) germination polymorphism (GP). HS is owing to the hard pericarp. PD is, in principle, a natural phenomenon that protects the seeds from precocious germination. For ger

  18. Proteomics of Arabidopsis seed germination and priming

    NARCIS (Netherlands)

    Gallardo, K.; Job, C.; Groot, S.P.C.; Puype, M.; Demol, H.; Vandekerckhove, J.; Job, D.

    2003-01-01

    To better understand seed germination, a complex developmental process, we developed a proteome analysis of the model plant Arabidopsis for which complete genome sequence is now available. Among about 1,300 total seed proteins resolved in two-dimensional gels, changes in the abundance (up- and down-

  19. Seed dormancy and germination: light and nitrate.

    NARCIS (Netherlands)

    Hilhorst, H.W.M.

    1990-01-01

    One of the most important aspects of the life cycle of seed plants is the formation and development of seeds on the motherplant and the subsequent dispersal. An equally important element of the survival strategy is the ability of seeds to prevent germination in unfavorable conditions, such as th

  20. Unravelling desiccation tolerance in germinated Arabidopsis seeds

    NARCIS (Netherlands)

    Maia de Oliveira, J.

    2014-01-01

    How different organisms survive in the absence or under very limited amounts of water is still an open question. The aim of the research presented in this thesis is to explore the molecular basis of desiccation tolerance in seeds. We investigated the possibilities of using germinated desiccation sen

  1. Seed priming with antioxidants improves sunflower seed germination and seedling growth under unfavorable germination conditions

    OpenAIRE

    DRAGANIC, Ivana; LEKIC, Slavoljub

    2014-01-01

    The results of studying the effects of sunflower seed priming with an aqueous solution of ascorbic acid (A), tocopherol (T), and glutathione (G) performed prior to accelerated ageing and a cold test are presented in this paper. Germination, the percentage of abnormal seedlings, and the lengths of both roots and shoots were monitored. The results showed that the cold test caused a drastic drop in germination, an adverse effect on the shoot length, an increase in the percentage of abnormal seed...

  2. Smoke-induced seed germination in California chaparral

    Science.gov (United States)

    Keeley, J.E.; Fotheringham, C.J.

    1998-01-01

    The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Heat shock triggers germination of certain species but has no stimulatory effect on a great many other postfire species that are chemically stimulated by combustion products. Previous reports have shown that charred wood will induce germination, and here we report that smoke also induces germination in these same species. Smoke is highly effective, often inducing 100% germination in deeply dormant seed populations with 0% control germination. Smoke induces germination both directly and indirectly by aqueous or gaseous transfer from soil to seeds. Neither nitrate nor ammonium ions were effective in stimulating germination of smoke-stimulated species, nor were most of the quantitatively important gases generated by biomass smoke. Nitrogen dioxide, however, was very effective at inducing germination in Caulanthus heterophyllus (Brassicaceae), Emmenanthe penduliflora (Hydrophyllaceae), Phacelia grandiflora (Hydrophyllaceae), and Silene multinervia (Caryophyllaceae). Three species, Dendromecon rigida (Papaveraceae), Dicentra chrysantha, and Trichostema lanatum (Lamiaceae), failed to germinate unless smoke treatment was coupled with prior treatment of 1 yr soil storage. Smoke-stimulated germination was found in 25 chaparral species, representing 11 families, none of which were families known for heat-shock-stimulated germination. Seeds of smoke-stimulated species have many analogous characteristics that separate them from most heat-shock-stimulated seeds, including: (1) outer seed coats that are highly textured, (2) a poorly developed outer cuticle, (3) absence of a dense palisade tissue in the seed coat, and (4) a subdermal membrane that is semipermeable, allowing water passage but blocking entry of large (molecular mass > 500) solutes. Tentative evidence suggests that permeability characteristics of this subdermal layer are altered by

  3. Investigation on carob seed germination under controlled conditions

    Directory of Open Access Journals (Sweden)

    Hamide GÜBBÜK

    2012-12-01

    Full Text Available In this study, the effects of some pre-treatments on seed germination of wild carob seeds were investigated under two different conditions (germination cabinet and greenhouse. Twenty two pre-treatments were applied to the seeds. Pre-treated and control seeds were placed under dark conditions at 25°C. All treated seeds were germinated at 27°C temperature in the germination cabinet and greenhouse conditions. Seed germination rate was determined according to the pre-treatments for both conditions. The results showed that if the seeds were soaked in pure (98 % or diluted sulphuric acid (H2SO4, 40 %, 90 % for 30 minutes then kept in water for 2 days or just soaking the seeds in H2SO4 sulfuric acid for 30 minute gave the best results in terms of seed germination as the seed germination rate was over 90 %. The lowest germination rate under both conditions was observed in the control and soaking the seeds in 60 % H2SO4 for 30 minutes. On the other hands, seeds soaked in 60 % H2SO4 and then kept in water for 2 days did not germinate as they lost germination ability. The highest germination rates were recorded after ten days of pre-treatments in both conditions.

  4. Germination and Dormancy in Annual Halophyte Juncus ranarius Song & Perr.

    Directory of Open Access Journals (Sweden)

    Jeremi KOŁODZIEJEK

    2015-12-01

    Full Text Available The effects of cold stratification and gibberellic acid (GA3 on dormancy breaking for seeds of the annual halophyte species Juncus ranarius were tested. Germination percentage and recovery responses of salt stressed seeds were also tested. Freshly collected seeds germinated slowly under all incubation conditions. Thus, the seeds of J. ranarius have physiological dormancy, e.g. they are water permeable, have a fully developed embryo and require cold stratification to come out of dormancy. Furthermore, promotion of germination by GA3 after-ripening in dry storage also indicated that these seeds have non-deep physiological dormancy. In general, the higher the GA3 concentration, the more germination occurred within the studied range. Juncus ranarius demonstrated a germination preference for light. The highest germination percentage and rate of germination were recorded under constant light conditions at 22 °C after 24 weeks of cold stratification. In saline solutions, the highest percentage of germination was obtained at 25 mM L-1 NaCl, and further increase in salinity resulted in a gradual decrease in germination. However, ungerminated seeds were not damaged by salt, showing a high level of recovery. The greater the reduction in salinity, the better the germination rate became. It was concluded that dormancy could be completely broken by cold stratification, indicating spring germination. Juncus ranarius can grow well at lower NaCl concentrations under constant light conditions at 22 °C.

  5. Bryophyte spore germinability is inhibited by peatland substrates

    Science.gov (United States)

    Bu, Zhao-Jun; Li, Zhi; Liu, Li-Jie; Sundberg, Sebastian; Feng, Ya-Min; Yang, Yun-He; Liu, Shuang; Song, Xue; Zhang, Xing-Lin

    2017-01-01

    Bryophyte substrates and species may affect spore germination through allelopathy. Polytrichum strictum is currently expanding in peatlands in north-eastern China - is this an effect of its superior spore germinability or do its gametophytes have a stronger allelopathic effect than do Sphagnum? We conducted a spore burial experiment to test the effect of species identity, substrate and water table depth (WTD) on spore germinability and bryophyte allelopathic effect with P. strictum and two Sphagnum species (S. palustre and S. magellanicum). After 5 months of burial during a growing season, the spores were tested for germinability. Allelopathic effect of bryophyte substrates was assessed by the difference between spore germinability after being stored inside or outside the substrates. After burial, more than 90% of the spores lost their germinability across all three species due to ageing and allelopathy. Spore germinability differed among species, where the spores in S. palustre had a higher germination frequency than those in P. strictum. The three bryophytes maintained a higher germinability in Sphagnum than in Polytrichum hummocks, probably due to a stronger allelopathic effect of P. strictum. Water table drawdown by 10 cm increased germinability by more than 60% across the three species. The study indicates that P. strictum does not possess an advantage regarding spore germination but rather its gametophytes have a stronger allelopathic effect. Due to the weaker inhibitive effect of Sphagnum gametophytes, P. strictum may have a potential establishment superiority over Sphagnum in peatlands, in addition to a better drought tolerance, which may explain its current expansion.

  6. Biochemical Changes During Seed Germination of Sterculia urens Roxb.

    Directory of Open Access Journals (Sweden)

    Botcha SATYANARAYANA

    2011-08-01

    Full Text Available The present study describes biochemical changes taking place during seed germination of Sterculia urens. The levels of proteins, total amino acids, reducing sugars, total soluble sugars and lipids were studied during various stages of seed germination (0-15 days. Total protein content was decreased in cotyledons during seed germination while free amino acid content increased to its maximum extent by 9th day of germination and reverse trend thereafter. The levels of reducing sugars and total soluble sugars increased till 6th day of germination and decreased thereafter. The lipid content was high at initial stages of germination (0-6 days but gradually decreased by 15th day of germination.

  7. A model for quantification of temperature profiles via germination times

    DEFF Research Database (Denmark)

    Pipper, Christian Bressen; Adolf, Verena Isabelle; Jacobsen, Sven-Erik

    2013-01-01

    Current methodology to quantify temperature characteristics in germination of seeds is predominantly based on analysis of the time to reach a given germination fraction, that is, the quantiles in the distribution of the germination time of a seed. In practice interpolation between observed...... time and a specific type of accelerated failure time models is provided. As a consequence the observed number of germinated seeds at given monitoring times may be analysed directly by a grouped time-to-event model from which characteristics of the temperature profile may be identified and estimated...... germination fractions at given monitoring times is used to obtain the time to reach a given germination fraction. As a consequence the obtained value will be highly dependent on the actual monitoring scheme used in the experiment. In this paper a link between currently used quantile models for the germination...

  8. Mechanisms of Induction of Germination of Bacillus subtilis Spores by High Pressure

    OpenAIRE

    Paidhungat, Madan; Setlow, Barbara; Daniels, William B.; Hoover, Dallas; Papafragkou, Efstathia; Setlow, Peter

    2002-01-01

    Spores of Bacillus subtilis lacking all germinant receptors germinate >500-fold slower than wild-type spores in nutrients and were not induced to germinate by a pressure of 100 MPa. However, a pressure of 550 MPa induced germination of spores lacking all germinant receptors as well as of receptorless spores lacking either of the two lytic enzymes essential for cortex hydrolysis during germination. Complete germination of spores either lacking both cortex-lytic enzymes or with a cortex not att...

  9. In vitro germination of desert rose varieties(

    Directory of Open Access Journals (Sweden)

    Tatiane Lemos Varella

    2015-08-01

    Full Text Available The drought stress resistance is a characteristic of the desert rose and its estimable beauty flowers, which gave it great relevance in the ornamental market. However, the desert rose production and germination is hampered by possible sterility of their male and female flowers and frequent problems in pollination, so the tissue culture is a promising alternative to the propagation of these plants. This study aimed to evaluate the effect of gibberellic acid on four commercial varieties of desert rose (Adenium obesum cultivated in vitro. The seeds of the varieties ‘Orange Pallet’, ‘Carnation violet’, ‘Diamond ring’ and ‘Vermiliont’ were sterilized and inoculated on Water + Agar (T0, medium MS (T1, ½ MS (T2, MS + 0.25 mg L-1 GA3 (T3, MS + 0.5 mg L-1 GA3 (T4, ½ MS + 0.25 mg L-1 GA3 (T5, ½ MS 0.5 mg L-1 GA3 (T6. The seeds germination of A. obesum was initiated on the fourth day of cultivation and on the tenth day was possible to observe the expansion of the cotyledons and leaf expansion with subsequent development of early secondary root. The ‘Orange pallet’ variety germinated 100% of seeds on water + agar and MS ½ + 0.5 mg L-1 of GA3. For ‘Diamond Ring’ and ‘Carnation violet’ the highest rate of germination occurred in treatments MS ½; 0.25 mg L-1 GA3; MS + 0.5 mg L-1 GA3 MS ½ + 0.5 mg L-1 GA3 averaging 80% and 70%, respectively. For ‘Vermiliont’ the best response was in MS and MS ½ + 0.5 mg L-1 GA3 ranging between 70-90% germinated embryos. It was registered different malformations in all treatments like absence of roots and apexes during seedling development. The concentrations of GA3 did not affect significantly the seed germination.

  10. EFFECTS OF PRE-GERMINATION TREATMENTS AND STORAGE ON GERMINATION OF Astronium fraxinifolium SCHOTT (ANACARDIACEAE DIASPORES

    Directory of Open Access Journals (Sweden)

    Lílian de Lima Braga

    2014-01-01

    Full Text Available The goal of this study was to evaluate the germination and the storage capacity of Astronium fraxinifolium diaspores. Six pre-germination treatments were used in the experiment: control treatment (intact diaspores; diaspores immersed in water at room temperature (25º C for 5 min; diaspores immersed in water at 70° C for 5 min; diaspores immersed in water at 100° C for 5 min; diaspores immersed in sodium hypochlorite solution (1:1000 for 2 min; and diaspores mechanically scarified with sandpaper #80. To evaluate storage conditions, we tested two different types of packaging (permeable paper bag and transparent glass jar and two environmental conditions (cold chamber and room conditions, resulting in four treatments. The germination tests were performed for zero (control and 60, 120, 180, 240, 300 and 360 days after storage. The effects of different treatments on germination and storage of diaspores were evaluated by ANOVA, followed by Tukey test. Regarding to pre-germination treatments, high germination rates were observed in the hypochlorite (98.0 ± 4.22%, control (97.0 ± 4.83%, water at room temperature (96.0 ± 6.99% and water at 70º C (83.0 ± 29.08% treatments. Thus, Astronium fraxinifolium diaspores do not present dormancy. During storage, the diaspores remained viable throughout the study period with high germination rates, except for the treatment in paper bags placed in the cold chamber, in which the diaspores lost their viability in the eighth month of storage. Therefore, this is not a recommended storage method for this species.

  11. EFFECTS OF PRE-GERMINATION TREATMENTS AND STORAGE ON GERMINATION OF Astronium fraxinifolium SCHOTT (ANACARDIACEAE DIASPORES

    Directory of Open Access Journals (Sweden)

    Lílian de Lima Braga

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814577The goal of this study was to evaluate the germination and the storage capacity of Astronium fraxinifolium diaspores. Six pre-germination treatments were used in the experiment: control treatment (intact diaspores; diaspores immersed in water at room temperature (25º C for 5 min; diaspores immersed in water at 70° C for 5 min; diaspores immersed in water at 100° C for 5 min; diaspores immersed in sodium hypochlorite solution (1:1000 for 2 min; and diaspores mechanically scarified with sandpaper #80. To evaluate storage conditions, we tested two different types of packaging (permeable paper bag and transparent glass jar and two environmental conditions (cold chamber and room conditions, resulting in four treatments. The germination tests were performed for zero (control and 60, 120, 180, 240, 300 and 360 days after storage. The effects of different treatments on germination and storage of diaspores were evaluated by ANOVA, followed by Tukey test. Regarding to pre-germination treatments, high germination rates were observed in the hypochlorite (98.0 ± 4.22%, control (97.0 ± 4.83%, water at room temperature (96.0 ± 6.99% and water at 70º C (83.0 ± 29.08% treatments. Thus, Astronium fraxinifolium diaspores do not present dormancy. During storage, the diaspores remained viable throughout the study period with high germination rates, except for the treatment in paper bags placed in the cold chamber, in which the diaspores lost their viability in the eighth month of storage. Therefore, this is not a recommended storage method for this species.

  12. Seed germination of Sierra Nevada postfire chaparral species

    Science.gov (United States)

    Keeley, Jon E.; McGinnis, Thomas W.; Bollens, Kim A.

    2005-01-01

    The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Here we report further germination experiments that elucidate the response of several widespread shrub species whose germination response was not clear and include other species from the Sierra Nevada, which have not previously been included in germination studies. The shrubs Adenostoma fasciculatum and Eriodictyon crassifolium and the postfire annualMentzelia dispersa exhibited highly significant germination in response to smoke treatments, with some enhanced germination in response to heating as well. The shrubs Fremontodendron californicum and Malacothamnus fremontii were stimulated only by heat-shock treatments. Seeds buried in the soil for one year exhibited substantially higher germination for controls and most treatments. In the case of two postfire annuals, Mimulus bolanderi and M. gracilipes, germination of fresh seed was significantly greater with smoke or heating but after soil storage, over two-thirds of the control seeds germinated and treatment effects were not significant. These two annuals are generally restricted to postfire conditions and it is suggested that control germination of soil-stored seed may be a light-response (which was not tested here) as previously reported for another chaparral species in that genus.

  13. Elucidating the germination transcriptional program using small molecules.

    Science.gov (United States)

    Bassel, George W; Fung, Pauline; Chow, Tsz-fung Freeman; Foong, Justin A; Provart, Nicholas J; Cutler, Sean R

    2008-05-01

    The transition from seed to seedling is mediated by germination, a complex process that starts with imbibition and completes with radicle emergence. To gain insight into the transcriptional program mediating germination, previous studies have compared the transcript profiles of dry, dormant, and germinating after-ripened Arabidopsis (Arabidopsis thaliana) seeds. While informative, these approaches did not distinguish the transcriptional responses due to imbibition, shifts in metabolism, or breaking of dormancy from those triggered by the initiation of germination. In this study, three mechanistically distinct small molecules that inhibit Arabidopsis seed germination (methotrexate, 2, 4-dinitrophenol, and cycloheximide) were identified using a small-molecule screen and used to probe the germination transcriptome. Germination-responsive transcripts were defined as those with significantly altered transcript abundance across all inhibitory treatments with respect to control germinating seeds, using data from ATH1 microarrays. This analysis identified numerous germination regulators as germination responsive, including the DELLA proteins GAI, RGA, and RGL3, the abscisic acid-insensitive proteins ABI4, ABI5, ABI8, and FRY1, and the gibberellin receptor GID1A. To help visualize these and other publicly available seed microarray data, we designed a seed mRNA expression browser using the electronic Fluorescent Pictograph platform. An overall decrease in gene expression and a 5-fold greater number of transcripts identified as statistically down-regulated in drug-inhibited seeds point to a role for mRNA degradation or turnover during seed germination. The genes identified in our study as responsive to germination define potential uncharacterized regulators of this process and provide a refined transcriptional signature for germinating Arabidopsis seeds.

  14. Gene Expression Profile Changes in Germinating Rice

    Institute of Scientific and Technical Information of China (English)

    Dongli He; Chao Han; Pingfang Yang

    2011-01-01

    Water absorption is a prerequisite for seed germination.During imbibition,water influx causes the resumption of many physiological and metabolic processes in growing seed.In order to obtain more complete knowledge about the mechanism of seed germination,two-dimensional gel electrophoresis was applied to investigate the protein profile changes of rice seed during the first 48 h of imbibition.Thirtynine differentially expressed proteins were identified,including 19 down-regulated and 20 up-regulated proteins.Storage proteins and some seed development- and desiccation-associated proteins were down regulated.The changed patterns of these proteins indicated extensive mobilization of seed reserves.By contrast,catabolism-associated proteins were up regulated upon imbibition.Semi-quantitative real time polymerase chain reaction analysis showed that most of the genes encoding the down- or upregulated proteins were also down or up regulated at mRNA level.The expression of these genes was largely consistent at mRNA and protein levels.In providing additional information concerning gene regulation in early plant life,this study will facilitate understanding of the molecular mechanisms of seed germination.

  15. Some physicochemical properties of flour from germinated sorghum grain.

    Science.gov (United States)

    Elkhalifa, Abd Elmoneim O; Bernhardt, Rita

    2013-02-01

    A Sudanese sorghum cultivar (Fetarita) was germinated for 3 days. Stability and clarity of sorghum pastes, freeze-thaw stability, gel consistency, and swelling power were measured every 24 h. There is no substantial difference in stability and clarity between flour samples from germinated and ungerminated sorghum, but a different behavior was observed between samples stored at room temperature and at 4 °C. Cooked paste derived from germinated sorghum flour presented higher syneresis than that derived from ungerminated sorghum flour over the first three cycles but when the cycle number increased, both flours showed zero syneresis value. For the gel consistency the flours derived from germinated sorghum produced thinnest gels. The neutral and acid gel consistency increased when the germination time increased. Germination had not much effect on the swelling power of sorghum flour.

  16. Effects of graphene on seed germination and seedling growth

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ming; Gao, Bin, E-mail: bg55@ufl.edu [University of Florida, Department of Agricultural and Biological Engineering (United States); Chen, Jianjun [University of Florida, Department of Environmental Horticulture and Mid-Florida Research & Education Center (United States); Li, Yuncong [University of Florida, Soil and Water Science Department Tropical Research & Education Center (United States)

    2015-02-15

    The environmental impact of graphene has recently attracted great attention. In this work, we show that graphene at a low concentration affected tomato seed germination and seedling growth. Graphene-treated seeds germinated much faster than control seeds. Analytical results indicated that graphene penetrated seed husks. The penetration might break the husks to facilitate water uptake, resulting in faster germination and higher germination rates. At the stage of seedling growth, graphene was also able to penetrate root tip cells. Seedlings germinated from graphene-treated seeds had slightly lower biomass accumulation than the control, but exhibited significantly longer stems and roots than the control, which suggests that graphene, in contrast with other nanoparticles, had different effects on seedling growth. Taken together, our results imply that graphene played complicated roles in affecting the initial stage of seed germination and subsequent seedling growth.

  17. Germination and outgrowth of spores of Bacillus cereus group members: diversity and role of germinant receptors.

    Science.gov (United States)

    Abee, Tjakko; Groot, Masja Nierop; Tempelaars, Marcel; Zwietering, Marcel; Moezelaar, Roy; van der Voort, Menno

    2011-04-01

    Bacillus cereus is a gram-positive, facultative anaerobic, endospore-forming toxicogenic human pathogen. Endospores are highly specialized, metabolically dormant cell types that are resistant to extreme environmental conditions, including heat, dehydration and other physical stresses. B. cereus can enter a range of environments, and can in its spore form, survive harsh conditions. If these conditions become favorable, spores can germinate and grow out and reach considerable numbers in a range of environments including processed foods. Certainly the last decade, when consumer preferences have shifted to mildly processed food, new opportunities arose for spore-forming spoilage and pathogenic organisms. Only rigorous methods have been shown to be capable of destroying all spores present in food, thus a shift toward e.g., milder heat preservation strategies, may result in low but significant amounts of viable spores in food products. Hence, the need for a mild spore destruction strategy is eminent including control of spore outgrowth. Consequently, there is a large interest in triggering spore germination in foodstuffs, since germinated spores have lost the extreme resistance of dormant spores and are relatively easy to kill. Another option could be to prevent germination so that no dangerous levels can be reached. This contribution will focus on germination and outgrowth characteristics of B. cereus and other members of the B. cereus group, providing an overview of the niches these spore-formers can occupy, the signals that trigger germination, and how B. cereus copes with these wake-up calls in different environments including foods, during food processing and upon interaction with the human host.

  18. Proteomic analyses of apoplastic proteins from germinating Arabidopsis thaliana pollen

    OpenAIRE

    Ge, Weina; Song, Yun; Zhang, Cuijun; Zhang, Yafang; Burlingame, Alma L; Guo, Yi

    2011-01-01

    Pollen grains play important roles in the reproductive processes of flowering plants. The roles of apoplastic proteins in pollen germination and in pollen tube growth are comparatively less well understood. To investigate the functions of apoplastic proteins in pollen germination, the global apoplastic proteins of mature and germinated Arabidopsis thaliana pollen grains were prepared for differential analyses by using 2-dimensional fluorescence difference gel electrophoresis (2-D DIGE) satura...

  19. The relation of morphology and affinity maturation in germinal centers

    CERN Document Server

    Meyer-Hermann, M

    2002-01-01

    The specific morphology of germinal centers is analyzed in the context of the optimization of the humoral immune response. The relevance of dark and light zones for the affinity maturation process is investigated in the framework of a theoretical model for the germinal center reaction. Especially, it is shown that an intermediate appearance of dark zones in germinal center reactions is advantageous for the process of antibody optimization.

  20. Evolution of 'smoke' induced seed germination in pyroendemic plants

    Science.gov (United States)

    Keeley, J. E.; Pausas, J.G.

    2016-01-01

    Pyroendemics are plants in which seedling germination and successful seedling recruitment are restricted to immediate postfire environments. In many fire-prone ecosystems species cue their germination to immediate postfire conditions. Here we address how species have evolved one very specific mechanism, which is using the signal of combustion products from biomass. This is often termed ‘smoke’ stimulated germination although it was first discovered in studies of charred wood effects on germination of species strictly tied to postfire conditions (pyroendemics). Smoke stimulated germination has been reported from a huge diversity of plant species. The fact that the organic compound karrikin (a product of the degradation of cellulose) is a powerful germination cue in many species has led to the assumption that this compound is the only chemical responsible for smoke-stimulated germination. Here we show that smoke-stimulated germination is a complex trait with different compounds involved. We propose that convergent evolution is a more parsimonious model for smoke stimulated germination, suggesting that this trait evolved multiple times in response to a variety of organic and inorganic chemical triggers in smoke. The convergent model is congruent with the evolution of many other fire-related traits.

  1. Glutathione synthesis is essential for pollen germination in vitro

    Science.gov (United States)

    2011-01-01

    Background The antioxidant glutathione fulfills many important roles during plant development, growth and defense in the sporophyte, however the role of this important molecule in the gametophyte generation is largely unclear. Bioinformatic data indicate that critical control enzymes are negligibly transcribed in pollen and sperm cells. Therefore, we decided to investigate the role of glutathione synthesis for pollen germination in vitro in Arabidopsis thaliana accession Col-0 and in the glutathione deficient mutant pad2-1 and link it with glutathione status on the subcellular level. Results The depletion of glutathione by buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis, reduced pollen germination rates to 2-5% compared to 71% germination in wildtype controls. The application of reduced glutathione (GSH), together with BSO, restored pollen germination and glutathione contents to control values, demonstrating that inhibition of glutathione synthesis is responsible for the decrease of pollen germination in vitro. The addition of indole-3-acetic acid (IAA) to media containing BSO restored pollen germination to control values, which demonstrated that glutathione depletion in pollen grains triggered disturbances in auxin metabolism which led to inhibition of pollen germination. Conclusions This study demonstrates that glutathione synthesis is essential for pollen germination in vitro and that glutathione depletion and auxin metabolism are linked in pollen germination and early elongation of the pollen tube, as IAA addition rescues glutathione deficient pollen. PMID:21439079

  2. [Research advance in seed germination of desert woody plants].

    Science.gov (United States)

    Chang, Wei; Wu, Jian-guo; Liu, Yan-hong

    2007-02-01

    This paper reviewed the research methods of desert woody plants seed germination, and the effects of internal and external ecological factors on it. Most researchers use incubator and artificial climate chamber to dispose the seeds, while field investigation was few involved. Seed dormancy is the important physiological factor affecting germination, while seed size, mass and color are closely correlated with its maturity and vigor. The poor permeability of seed capsule is a barrier that restrains the germination, which can be weakened or eliminated by shaving, cutting, treating with low temperature, and dipping in chemical reagent, etc. Seed water content has a close correlation with its storage life and water-absorbing capability. Suitable temperature is the prerequisite of seed germination, while changing temperature can accelerate the germination. Soil moisture content is a limiting factor, while illumination is not so essential to the seed germination of most desert woody plants. Sand-burying plays an important role in the seed germination through regulating illumination, temperature, and soil moisture content. Salinity stress restrains the seed germination of desert woody plants observably. In further studies, the effects of multi-factors and the eco-physiological and molecular biological mechanisms of germination should be more concerned.

  3. Effect of temperature and pre-germination treatments on seed germination and seedling vigor of Jatropha curcas L

    Directory of Open Access Journals (Sweden)

    Thais Cremon

    2012-09-01

    Full Text Available To date, there are no official methods used to test the seed germination of physic nut (Jatropha curcas and there have only been a few attempts to optimize the germination of this species. The objective of this study was to evaluate the effect of different temperatures and pre-germination treatments on the germination and seedling vigor of J. curcas. The treatments were arranged in a completely randomized factorial scheme with four temperatures (20, 25, 30 and 20-30°C x two types of seeds (with and without the seed tegument x six periods of water imbibition (0, 6, 12, 18, 24 and 30h. The seeds were sown using a roller system with four replications of 50 seeds for each treatment. The germination percentage was higher for seeds stored at 25°C, when the seed tegument was maintained. When the time of water imbibition was increased, the germination percentage decreased, as well as the index of germination velocity and the percentage of germination of the first count. Imbibition for up to 12h led to an increase in hypocotyl growth. For this species, the maximum germination potential and highest vigor were obtained at 25°C, for seeds with teguments that were maintained and were not submitted to water imbibition.

  4. Impact of sorbic acid on germinant receptor-dependent and -independent germination pathways in Bacillus cereus

    NARCIS (Netherlands)

    Melis, van C.C.J.; Nierop Groot, M.N.; Abee, T.

    2011-01-01

    Amino acid- and inosine-induced germination of Bacillus cereus ATCC 14579 spores was reversibly inhibited in the presence of 3 mM undissociated sorbic acid. Exposure to high hydrostatic pressure, Ca-dipicolinic acid (DPA), and bryostatin, an activator of PrkC kinase, negated this inhibition,

  5. Dynamics of B cells in germinal centres.

    Science.gov (United States)

    De Silva, Nilushi S; Klein, Ulf

    2015-03-01

    Humoral immunity depends on the germinal centre (GC) reaction during which somatically mutated high-affinity memory B cells and plasma cells are generated. Recent studies have uncovered crucial cues that are required for the formation and the maintenance of GCs and for the selection of high-affinity antibody mutants. In addition, it is now clear that these events are promoted by the dynamic movements of cells within and between GCs. These findings have resolved the complexities of the GC reaction in greater detail than ever before. This Review focuses on these recent advances and discusses their implications for the establishment of humoral immunity.

  6. Osmopriming duration in Araçá-boi seeds germination

    Directory of Open Access Journals (Sweden)

    Marcela Liege da Silva

    2016-06-01

    Full Text Available The Araca-boi is a native fruit of the Amazon region and its fruits have great potential for agro-industrial use due to the intrinsic characteristics of the pulp. The seeds are dormant and the primary cause could be due to the presence of inhibiting chemicals germination and can also be caused by the impermeability in tegument. The objective of this study was to assess the osmopriming efficiency promoted by Sucrose (C12H22O11 and Potassium Nitrate (KNO3 on germination of seeds of araca-boi in different immersion times. Thus, the seeds were osmoconditioned in following solutions: C12H22O11, KNO3 , KNO3 + C12H22O11 and H2 O, by period of 6, 12 and 24 h. Throughout of 70 days were evaluated the germination percentage and germination rate (index. The experiment is based on a completely randomized in a factorial analysis 4x3 with four replications of 10 seeds. The osmopriming of Araca-boi seed in KNO3 solution was shown to be efficient both to promote germination and the germination rate. The Araca-boi seeds osmoconditioned in KNO3 solution has an average efficiency of 99% in the germination percentage up to 70 days. The osmopriming period showed no influence on seed germination of the seeds of Araca-boi.

  7. Temperature and substrate on Plukenetia volubilis L. seed germination

    Directory of Open Access Journals (Sweden)

    Givanildo Z. da Silva

    Full Text Available ABSTRACT The objective of this work was to evaluate the effect of temperature and substrate on the germination of P. volubilis seeds. Seeds harvested from 25 matrix plants were submitted, in two studies, to conditions of (i sowing in rolled paper towel at the temperatures of 10, 15, 20, 25, 30, 35, 40, and 45 °C, for the evaluation of germination, first count of germination, germination speed index and mean time for germination, and (ii sowing in the substrates paper towel, sand, Bioplant®, Bioplant® and micron, superfine, fine, medium and coarse vermiculite. The same evaluations mentioned in the first study were conducted at the temperature of 30 oC, as well as plant growth. The treatment replicates were distributed in a completely randomized block design and the effects of temperature were compared by polynomial regression analysis. The substrates were compared by the Scott-Knott test at 0.05 probability level. The data show that the ideal range of temperature for the germination of P. volubilis is between 25 and 30 °C. The temperature of 20 °C is the minimum for germination and those above 35 °C are lethal to these seeds. The most favorable substrate for P. volubilis seed germination is micron or fine vermiculite.

  8. Investigating the Influence of Karrikins on Seed Germination

    Science.gov (United States)

    de Beer, Josef

    2012-01-01

    Recent research has identified a karrikin (a butenolide derative) known as 3-methyl-2H-furo[2,3-c]pyran-2-one, formed from burning cellulose, that stimulates seed germination. Here, I present ideas on how to investigate the influence of karrikins on seed germination in the laboratory.

  9. [Malignant germinal tumours of the mediastinum: diagnosis and treatment].

    Science.gov (United States)

    Lemarié, E

    2004-11-01

    Mediastinal germinal tumours are composed of tissues resembling those that follow one another during embryo development, by differentiation of the primordial and extraembryonic layers. Such practice separates the mature teratomas (benign), seminomas and non-seminomatous germinal tumours (NSGT). Platin-based chemotherapy has shattered the prognosis of such tumours.

  10. Radish (Raphanus sativus) seed size affects germination response to coumarin

    Science.gov (United States)

    The inhibition of seed germination by an allelochemical is generally greater in small seeds than in large seeds. Studies reporting these results used a large number of plant species that varied in seed size, which might have introduced differences in germination characteristics or various parameter...

  11. Investigating the Influence of Karrikins on Seed Germination

    Science.gov (United States)

    de Beer, Josef

    2012-01-01

    Recent research has identified a karrikin (a butenolide derative) known as 3-methyl-2H-furo[2,3-c]pyran-2-one, formed from burning cellulose, that stimulates seed germination. Here, I present ideas on how to investigate the influence of karrikins on seed germination in the laboratory.

  12. Germinal center reaction: antigen affinity and presentation explain it all.

    Science.gov (United States)

    Oropallo, Michael A; Cerutti, Andrea

    2014-07-01

    The selection and expansion of B cells undergoing affinity maturation in the germinal center is a hallmark of humoral immunity. A recent paper in Nature provides new insights into the relationships between the affinity of the immunoglobulin receptor for antigen, the ability of B cells to present antigen to T cells, and the processes of selection, mutation, and clonal expansion in the germinal center.

  13. Role of ethylene in the germination metabolism of ricinus communis

    Science.gov (United States)

    Cristescu, Simona; Dumitras, Dan C.; Godeanu, Adriana

    1999-03-01

    A CO2 laser-based photoacoustic method has been used to monitor the ethylene (C2H4) released by castor bean (Ricinus communis) seeds during germination. The relationship between the evolution of the C2H4 germinating seeds and the respiration intensity is presented.

  14. Coffee (Coffea arabica cv. Rubi) seed germination : mechanism and regulation

    NARCIS (Netherlands)

    Silva, da E.A.A.

    2002-01-01

     Coffee seeds display slow and variable germination which severely hampers the production of seedlings for planting in the following growth season. Little work has been done with the aim to understand the behavior of coffee seeds during germination and there is a

  15. Dynamic Proteomic Insights of Seed Germination

    Institute of Scientific and Technical Information of China (English)

    Marc Galland; Romain Huguet; Erwann Arc; Gwendal Cueff; Dominique Job; Lo(i)c Rajjou

    2012-01-01

    Proteome analysis,which involves the identification and characterization of expressed proteins,is a powerful tool for determining the biological roles and functions of individual proteins.Furthermore,by providing a systematic and without any a priori mean for large-scale identification of cellular proteins,proteomics is expected to accelerate discoveries in complex processes such as plant development.Our research activity is mainly focused on the "Functional proteomics" approach in the field of seed biology.We are developing a proteome analysis of the model plant,Arabidopsis thaliana,in order to investigate seed development,dormancy,germination and longevity and identify related changes in the seed proteome.Combined approaches associating classical 2D gel-based proteome and dynamic radiolabeled proteome disclosed data regarding protein turnover and protein stability (http://www.seed-proteome.com).The selective translation of mRNAs emerges as an important mechanism regulating molecular functions involved in the control of seed germination.

  16. Mitochondrial biogenesis in plants during seed germination.

    Science.gov (United States)

    Law, Simon R; Narsai, Reena; Whelan, James

    2014-11-01

    Mitochondria occupy a central role in the eukaryotic cell. In addition to being major sources of cellular energy, mitochondria are also involved in a diverse range of functions including signalling, the synthesis of many essential organic compounds and a role in programmed cell death. The active proliferation and differentiation of mitochondria is termed mitochondrial biogenesis and necessitates the coordinated communication of mitochondrial status within an integrated cellular network. Two models of mitochondrial biogenesis have been defined previously, the growth and division model and the maturation model. The former describes the growth and division of pre-existing mature organelles through a form of binary fission, while the latter describes the propagation of mitochondria from structurally and biochemically simple promitochondrial structures that upon appropriate stimuli, mature into fully functional mitochondria. In the last decade, a number of studies have utilised seed germination in plants as a platform for the examination of the processes occurring during mitochondrial biogenesis. These studies have revealed many new aspects of the tightly regulated procession of events that define mitochondrial biogenesis during this period of rapid development. A model for mitochondrial biogenesis that supports the maturation of mitochondria from promitochondrial structures has emerged, where mitochondrial signalling plays a crucial role in the early steps of seed germination.

  17. Starch bioengineering affects cereal grain germination and seedling establishment

    DEFF Research Database (Denmark)

    Shaik, Shahnoor Sultana; Carciofi, Massimiliano; Martens, Helle Juel;

    2014-01-01

    Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule...... structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics...... showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and β-glucan (BG) degradation was stimulated...

  18. Evaluation of homeopathy in seed germination of yellow ipe

    Directory of Open Access Journals (Sweden)

    Naira Maranhão Silva

    2014-09-01

    Full Text Available Studies with homeopathie on seed germination of native forest species are scarce, regardless of its potential as low impact technology. Therefore, the objective of this study was to evaluate the use of homeopathic medications in different dynamizations in the seed germination of yellow ipe. The experimental design was completely randomized with three replications, in a factorial scheme with the three medicines in five dynamizations, totaling 16 treatments with the control consisting of distilled water. The medications used were Calcarea carbonica, Carbo vegetabilis and Silicea. The mediations were applied in of 6, 12, 30, 100 and 200 centesimals hahnemanianas (CH dynamizations. Regarding germination percentage and speed of germination index the medicament Silicea in 12CH dynamization was less efficient when compared to others medications and dynamizations. The use of homeopathic preparations does not benefit the pattern of yellow ipe seeds germination.

  19. Stromal networking: cellular connections in the germinal centre.

    Science.gov (United States)

    Denton, Alice E; Linterman, Michelle A

    2017-03-17

    Secondary lymphoid organs are organized into distinct zones, governed by different types of mesenchymal stromal cells. These stromal cell subsets are critical for the generation of protective humoral immunity because they direct the migration of, and interaction between, multiple immune cell types to form the germinal centre. The germinal centre response generates long-lived antibody-secreting plasma cells and memory B cells which can provide long-term protection against re-infection. Stromal cell subsets mediate this response through control of immune cell trafficking, activation, localization and antigen access within the secondary lymphoid organ. Further, distinct populations of stromal cells underpin the delicate spatial organization of immune cells within the germinal centre. Because of this, the interactions between immune cells and stromal cells in secondary lymphoid organs are fundamental to the germinal centre response. Herein we review how this unique relationship leads to effective germinal centre responses.

  20. Development of a cell line from Echinococcus granulosus germinal layer.

    Science.gov (United States)

    Albani, Clara María; Cumino, Andrea Carina; Elissondo, María Celina; Denegri, Guillermo María

    2013-10-01

    In vitro culture of parasitic helminths provides an important tool to study cell regeneration and physiology, as well as for molecular biology and genetic engineering studies. In the present study, we established in vitro propagation of cells from Echinococcus granulosus germinal cyst layer. E. granulosus germinal cells grew beyond 100 passages and showed no signs of reduced proliferation capacity. Microscopic analysis revealed that cells grew both attached to the substrate and in suspension, forming three-dimensional structures like mammalian stem cell aggregates. Examination of the chromosome number of attached germinal cells showed a high degree of heteroploidy, suggesting the occurrence of transformation during culture. Monolayer cells survived cryopreservation and were able to proliferate after thawing. Based on the characteristics displayed by E. granulosus germinal cells, we establish a cell line from the E. granulosus germinal layer. Furthermore, we propose that this cell line could be useful for drug screening and for obtaining parasite material.

  1. Coordination of seed dormancy and germination processes by MYB96.

    Science.gov (United States)

    Lee, Kyounghee; Seo, Pil Joon

    2015-01-01

    The transition between seed dormancy and germination is an important stage that initiates plant life cycle. Hormonal balances of abscisic acid (ABA) and gibberellin (GA) contribute to determining the proper timing to germinate. Here, we demonstrate that the R2R3-type MYB96 transcription factor, a key ABA signaling mediator, coordinates seed dormancy and germination processes through distinct downstream events. This transcription factor controls ABA-INSENSITIVE 4 (ABI4) expression to inhibit seed germination by suppressing breakdown of lipid reserves in embryo. In addition, it also induces seed dormancy by stimulating ABA biosynthesis in an ABI4-independent manner. We propose that MYB96 integrates a multitude of environmental stress signals and acts as a master regulator in the determination of timing for seed germination.

  2. Pre-treating Seed to Enhance Germination of Desert Shrubs

    Energy Technology Data Exchange (ETDEWEB)

    W. K. Ostler; D. C. Anderson; D. J. Hansen

    2002-06-01

    Creosotebush [Larrea tridentata (D.C.) Cav.] and white bursage [Ambrosia dumosa (A. Gray) W.W. Payne] seeds were subjected to pre-treatments of rinsing and soaking in water and thiourea to enhance germination in laboratory experiments. The effects of darkness, temperature, seed source, and soil moisture were also evaluated in the laboratory. The best pre-treatment from the laboratory experiments, rinsing with water for 36 hours followed by drying, was field-tested at Fort Irwin, California. Two sites and two seeding dates (early March and mid April) were determined for each site. Five mulch treatments (no mulch, straw, gravel, chemical stabilizer, and plastic) were evaluated in combination with the seed pre-treatments. Field emergence was greatly enhanced with the seed pre-treatment for white bursage during the March (18-42% increase in germination) and April seedings (16-23% increase in germination). Creosotebush showed poor germination during March (2-5%) when soil temperatures averaged 15 C, but germination increased during the April trials (6-43%) when soil temperatures averaged 23 C. The seed pre-treatment during the April trials increased germination from 16-23%. The plastic mulch treatment increased germination dramatically during both the March and April trials. The plastic mulch increased soil temperatures (8-10 C)and maintained high humidity during germination. Both the chemical stabilizer and the gravel mulches improved germination over the control while the straw mulch decreased germination. These results suggest that seed pre-treatments combined with irrigation and mulch are effective techniques to establish these two dominant Mojave Desert species from seed.

  3. Hydrolysis of cortex peptidoglycan during bacterial spore germination.

    Science.gov (United States)

    Makino, Shio; Moriyama, Ryuichi

    2002-06-01

    Despite the most extreme dormancy and resistance properties among living systems, bacterial endospores retain an alert sensory mechanism to respond to the germinants and initiate germination. Although the molecular mechanism of the germination process is not completely described, current progress in the studies on the enzymes involved in the process gave us a somewhat clearer picture of the process of spore peptidoglycan (cortex) hydrolysis, a major biochemical event in germination. Germination-specific cortex-lytic enzymes require muramic acid d-lactam in their substrates. At least two types of enzymes are involved in the germination process: a spore cortex-lytic enzyme (SCLE) and a cortical fragment-lytic enzyme (CFLE). Except for their peptidoglycan-binding regions, the primary structures of SCLE and CFLE vary according species. Both enzymes differ in their hydrolytic bond-specificities and recognition of the substrates morphology. SCLE appears to initiate germination by uncrosslinking the intract cortex, and the CFLE further degrades the polysaccharide moiety of the SCLE-modified cortex. In vivo CFLE activity is likely regulated by its requirement for partially un-crosslinked cortex, while SCLE requires activation process. Clostridium perfringens SCLE is activated by a germination-specific serine protease during germination, but the activation mechanism of SCLE in Bacillus species is unknown. Cortex-lytic enzymes are expressed at the early stage of sporulation but the compartment of expression depends on proteins. However, all enzymes are located outside the cortex layer in dormant spores, suggesting that the hydrolysis process initiates at the exterior side of the cortex. The assembly of the germination apparatus is also discussed.

  4. Association mapping of soybean seed germination under salt stress.

    Science.gov (United States)

    Kan, Guizhen; Zhang, Wei; Yang, Wenming; Ma, Deyuan; Zhang, Dan; Hao, Derong; Hu, Zhenbin; Yu, Deyue

    2015-12-01

    Soil salinity is a serious threat to agriculture sustainability worldwide. Seed germination is a critical phase that ensures the successful establishment and productivity of soybeans in saline soils. However, little information is available regarding soybean salt tolerance at the germination stage. The objective of this study was to identify the genetic mechanisms of soybean seed germination under salt stress. One natural population consisting of 191 soybean landraces was used in this study. Soybean seeds produced in four environments were used to evaluate the salt tolerance at their germination stage. Using 1142 single-nucleotide polymorphisms (SNPs), the molecular markers associated with salt tolerance were detected by genome-wide association analysis. Eight SNP-trait associations and 13 suggestive SNP-trait associations were identified using a mixed linear model and the TASSEL 4.0 software. Eight SNPs or suggestive SNPs were co-associated with two salt tolerance indices, namely (1) the ratio of the germination index under salt conditions to the germination index under no-salt conditions (ST-GI) and (2) the ratio of the germination rate under salt conditions to the germination rate under no-salt conditions (ST-GR). One SNP (BARC-021347-04042) was significantly associated with these two traits (ST-GI and ST-GR). In addition, nine possible candidate genes were located in or near the genetic region where the above markers were mapped. Of these, five genes, Glyma08g12400.1, Glyma08g09730.1, Glyma18g47140.1, Glyma09g00460.1, and Glyma09g00490.3, were verified in response to salt stress at the germination stage. The SNPs detected could facilitate a better understanding of the genetic basis of soybean salt tolerance at the germination stage, and the marker BARC-021347-04042 could contribute to future breeding for soybean salt tolerance by marker-assisted selection.

  5. Analysis of germination capacity and germinant receptor (sub)clusters of genomesequenced Bacillus cereus environmental isolates and model strains

    NARCIS (Netherlands)

    Warda, Alicja K.; Xiao, Yinghua; Boekhorst, Jos; Wells-Bennik, Marjon H.J.; Nierop Groot, Masja N.; Abee, Tjakko

    2017-01-01

    Spore germination of 17 Bacillus cereus food isolates and reference strains was evaluated using flow cytometry analysis in combination with fluorescent staining at a single-spore level. This approach allowed for rapid collection of germination data under more than 20 conditions, including heat ac

  6. Effects of nitrogen ion implantation on lily pollen germination and the distribution of the actin cytoskeleton during pollen germination

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effects of low energy nitrogen ion implantation on lily (Lilium davidii Duch.) pollen germination and the distribution of the actin cytoskeleton during pollen germination have been studied. Preliminary results showed that the ratio of pollen germination increased from (16.0±1.6)% to (27.0±2.1)% when implanted with nitrogen ions by 100 keV and a dose of 1013 ions/cm2. Further experiments were performed by staining the actin filaments in pollen with rhodamine-phalloidin and detected by using laser confocol microscopy. After hydration for 10 h, the actin filaments in ion implanted pollen grains tended to form thick bundles oriented in parallel or ring shape at the germinal furrow, indicating that the effect of nitrogen ion implantation on the germination of pollen might be mediated by reorganization of the actin cytoskeleton.

  7. Preparation and Photocatalytic Property of ZnO Nanoparticles via Non-Ionic Surfactant Dodecylamine Assisted Hydrothermal Method%非离子表面活性剂十二胺辅助水热合成氧化锌纳米粉体及其光催化性能研究

    Institute of Scientific and Technical Information of China (English)

    陈婷; 徐彦乔; 江莞; 江伟辉; 谢志翔

    2016-01-01

    Zinc oxide nanoparticles were prepared via hydrothermal method at 160℃for 24 h using zinc chloride as raw material, ammonia as alkali source and non-ionic surfactant dodecylamine (DDA) as template, respectively. The phase of the resulting product was investigated by X-ray diffraction (XRD), while the morphology and microstructure were characterized by ifeld emission scanning electron microscope (FESEM) and high resolution transmission electron microscopy (HRTEM), respectively. The experimental results show that all the samples are pure zinc oxides with hexagonal wurtzite structure. The samples in the absence of DDA were nanorods with 2-10μm in length and 0.5-0.8 μm in diameter. Increasing the DDA amount, the homogeneity of the samples is increased, and the morphology was changed from nanorods to nanoparticles with the particle size about 80-100 nm. The nanoparticles exhibited excellent photocatalytic ability at room temperature. After 120 min irradiation, the degradation degree of 10 mg/L Congo red dye was close to 100%.%以氯化锌为原料、氨水为碱源,添加非离子表面活性剂十二胺(DDA)为模板剂经160℃水热24 h制备了氧化锌纳米粉体。通过X射线衍射(XRD)分析了产物的组成结构,并采用场发射扫描电子显微镜(FESEM)和高分辨透射电子显微镜(HRTEM)对样品的显微形貌进行了表征。实验结果表明,制备的样品为六方纤锌矿结构的氧化锌。在不添加DDA的条件下,水热产物为长2-10μm、直径0.5-0.8μm的一维纳米棒;随着DDA添加量的增大,样品的均匀性提高,同时由纳米棒转变为纳米颗粒,粒径大小为80-100 nm。室温下该纳米颗粒具有优异的光催化性能,在光照240 min后对质量浓度为10 mg/L的刚果红的降解率达到100%。

  8. Effect of different germination conditions on antioxidative properties and bioactive compounds of germinated brown rice.

    Science.gov (United States)

    Lin, You-Tung; Pao, Cheng-Cheng; Wu, Shwu-Tzy; Chang, Chi-Yue

    2015-01-01

    This study investigates antioxidative activity and bioactive compounds of ungerminated brown rice (UBR) and germinated brown rice (GBR). We used two rice cultivars (Oryza sativa L.), Taiwan Japonica 9 (TJ-9) and Taichung Indica 10 (TCI-10), as the materials in our experiments. The conditions for inducing germination are soaking time in water 24, 48, or 72 h; temperature 26 or 36°C; incubation in light or darkness; and open or closed vessels, in which the antioxidative activities and bioactive compounds of GBR were determined. We found that, in order to maximize antioxidative activity and bioactive compounds, germination should be under higher temperature (36°C), long soaking time (72 h), darkness, and closed vessel. GBR contains much higher levels of antioxidative activity and bioactive compounds than ungerminated brown rice (UBR). We found a strong correlation between antioxidative activities (DPPH radical scavenging ability, reducing power, and Trolox equivalent antioxidant capacity) and bioactive compounds (γ-oryzanols, tocopherol, and tocotrienol). Higher temperature (36°C) is also conducive to the production of GABA in GBR. These results are considered very useful research references for the development of future functional foods and additives.

  9. In vitro culture and germination of terrestrial Asian orchid seeds.

    Science.gov (United States)

    Lee, Yung-I

    2011-01-01

    Orchidaceae is one of the largest families of flowering plants, and many of its species are highly valuable as herbal medicines and to the horticultural industry. To meet commercial requirements and to conserve natural resources, in vitro seed germination has been utilized to produce large quantities of uniform seedlings. In general, terrestrial orchid seeds are more difficult to germinate and grow than epiphytic orchids. Terrestrial orchid seeds have a hardened seed coat and more stringent requirements for germination in vitro. In this chapter, we document the timing of seed collection and pretreatments for improving in vitro germination of some terrestrial Asian orchids. The process of in vitro germination is demonstrated, including (1) the culture of immature seeds; (2) the culture of mature seeds; and (3) subsequent seedling development. For immature seed culture, optimal timing of seed harvest is key to maximizing germination; for mature seed culture, selection of adequate pretreatment conditions (i.e., the duration and concentrations of pretreatment solutions) is essential to improve germination.

  10. Proteomic analyses of apoplastic proteins from germinating Arabidopsis thaliana pollen.

    Science.gov (United States)

    Ge, Weina; Song, Yun; Zhang, Cuijun; Zhang, Yafang; Burlingame, Alma L; Guo, Yi

    2011-12-01

    Pollen grains play important roles in the reproductive processes of flowering plants. The roles of apoplastic proteins in pollen germination and in pollen tube growth are comparatively less well understood. To investigate the functions of apoplastic proteins in pollen germination, the global apoplastic proteins of mature and germinated Arabidopsis thaliana pollen grains were prepared for differential analyses by using 2-dimensional fluorescence difference gel electrophoresis (2-D DIGE) saturation labeling techniques. One hundred and three proteins differentially expressed (p value≤0.01) in pollen germinated for 6h compared with un-germination mature pollen, and 98 spots, which represented 71 proteins, were identified by LC-MS/MS. By bioinformatics analysis, 50 proteins were identified as secreted proteins. These proteins were mainly involved in cell wall modification and remodeling, protein metabolism and signal transduction. Three of the differentially expressed proteins were randomly selected to determine their subcellular localizations by transiently expressing YFP fusion proteins. The results of subcellular localization were identical with the bioinformatics prediction. Based on these data, we proposed a model for apoplastic proteins functioning in pollen germination and pollen tube growth. These results will lead to a better understanding of the mechanisms of pollen germination and pollen tube growth.

  11. T-cell subsets in the germinal center.

    Science.gov (United States)

    Ramiscal, Roybel R; Vinuesa, Carola G

    2013-03-01

    T cells are known to migrate to B-cell-enriched follicles and germinal centers within secondary lymphoid organs to provide help to B cells. Cognate T:B interactions that take place at the T:B border and subsequently within germinal centers are essential for B-cell priming, differentiation into germinal center B cells, and selection of mutated cells into memory B cells or memory plasma cells. In recent years, different stages of maturation within B-cell helper T cells, collectively known as B-follicular helper T (Tfh) cells, as well as heterogeneity amid germinal center T cells are becoming clear. Indeed, germinal centers support not only bona fide Tfh cells but also CD4(+) and CD8(+) follicular regulatory T (Tfr) cells that act to suppress germinal center responses and B-cell helper natural killer T cells. There is a growing need for more precise phenotypic and functional distinction of these specialized T-cell subsets. In this review, we summarize current knowledge on the ontogeny, molecular identity, and functional relevance of the various subsets of germinal center T cells.

  12. Involvement of Alternative Splicing in Barley Seed Germination.

    Science.gov (United States)

    Zhang, Qisen; Zhang, Xiaoqi; Wang, Songbo; Tan, Cong; Zhou, Gaofeng; Li, Chengdao

    2016-01-01

    Seed germination activates many new biological processes including DNA, membrane and mitochondrial repairs and requires active protein synthesis and sufficient energy supply. Alternative splicing (AS) regulates many cellular processes including cell differentiation and environmental adaptations. However, limited information is available on the regulation of seed germination at post-transcriptional levels. We have conducted RNA-sequencing experiments to dissect AS events in barley seed germination. We identified between 552 and 669 common AS transcripts in germinating barley embryos from four barley varieties (Hordeum vulgare L. Bass, Baudin, Harrington and Stirling). Alternative 3' splicing (34%-45%), intron retention (32%-34%) and alternative 5' splicing (16%-21%) were three major AS events in germinating embryos. The AS transcripts were predominantly mapped onto ribosome, RNA transport machineries, spliceosome, plant hormone signal transduction, glycolysis, sugar and carbon metabolism pathways. Transcripts of these genes were also very abundant in the early stage of seed germination. Correlation analysis of gene expression showed that AS hormone responsive transcripts could also be co-expressed with genes responsible for protein biosynthesis and sugar metabolisms. Our RNA-sequencing data revealed that AS could play important roles in barley seed germination.

  13. Studies on the molecular mechanisms of seed germination.

    Science.gov (United States)

    Han, Chao; Yang, Pingfang

    2015-05-01

    Seed germination that begins with imbibition and ends with radicle emergence is the first step for plant growth. Successful germination is not only crucial for seedling establishment but also important for crop yield. After being dispersed from mother plant, seed undergoes continuous desiccation in ecosystem and selects proper environment to trigger germination. Owing to the contribution of transcriptomic, proteomic, and molecular biological studies, molecular aspect of seed germination is elucidated well in Arabidopsis. Recently, more and more proteomic and genetic studies concerning cereal seed germination were performed on rice (Oryza sativa) and barley (Hordeum vulgare), which possess completely different seed structure and domestication background with Arabidopsis. In this review, both the common features and the distinct mechanisms of seed germination are compared among different plant species including Arabidopsis, rice, and maize. These features include morphological changes, cell and its related structure recovery, metabolic activation, hormone behavior, and transcription and translation activation. This review will provide more comprehensive insights into the molecular mechanisms of seed germination.

  14. Evolution of nutrient ingredients in tartary buckwheat seeds during germination.

    Science.gov (United States)

    Yiming, Zhou; Hong, Wang; Linlin, Cui; Xiaoli, Zhou; Wen, Tang; Xinli, Song

    2015-11-01

    Evolution of nutrient components and the antioxidative activity of seed sprouts of tartary buckwheat (Fagopyrum tataricum L. Gaertn) were investigated in the course of germination. Results showed that the contents of total flavonoids increased with germination time and leveled off after the third germination day with the changing trend of rutin and quercetin opposite to each other. The decrease of total protein and total sugar contents in the germinated seeds was accompanied respectively by an increase of amino acid and reducing sugar contents. The contents of vitamin C (Vc) and B1(V(B1)) exhibited a minimum with no appreciable changes found for vitamin B(2) (V(B2)) and B(6) (V(B6)). The contents of total chlorophyll, chlorophyll A and B all exhibited a maximum on the fifth germination day. The contents of fatty acids had no regular changing trend with germination time. The free radical-scavenging activities of the seeds increased with germination time and were caused by an increase in their antioxidative activity.

  15. Germination traits of three weed species in Kosovo

    Directory of Open Access Journals (Sweden)

    A. Mehmeti

    2010-02-01

    Full Text Available Amaranthus retroflexus, Echinochloa crus-galli and Datura stramonium are the most important weed species in Kosovo. They cause severe yield depression, contaminate fodder and negatively affect growth and reproduction of other weed species. To counteract these problems, specific strategies need to be developed. Such strategies should consider information on species germination traits. In this context, our study provides information on temperature requirements for germination. Seeds of A. retroflexus, E. crus-galli and D. stramonium were harvested in two sub-regions of Kosovo (western and eastern parts differing in climate and land use. They were set for germination experiments in growth chambers at temperatures ranging from 3 to 35 °C and under field conditions. In both experiments, the germination rate differed between species and provenances. In the growth chamber experiment, germination of all three species was negligible below 15 °C and reached the highest rates between 24 and 30 °C. Seeds originating from the western part of Kosovo had higher germination rates and required a lower temperature for germination than seeds originating from the eastern part. In the field experiment, the time-dependent germination behaviour of D. stramonium differed between provenances. In general, germination started when soil temperature was above 18 °C and continued as long as the soil was moist. The results are discussed in the context of the need to develop weed management strategies against these weeds in Kosovo.

  16. Effects of UV-irradiation on seed germination.

    Science.gov (United States)

    Noble, Rudolf E

    2002-11-01

    The advent of depletion of the ozone layer with the reported subsequent increase of UV-irradiation has led to heightened interest in the effects of UV light on cellular organisms. In this study, the effects of UV-irradiation was studied on the germination of kale, cabbage, radish and agave seeds. In all cases, UV light sped the germination of these seeds but the subsequent growth of the seedlings was markedly retarded. Pictures, taken at day 15, are presented to show this latter effect and the possible effects of UV-irradiation on seed germination are discussed.

  17. Effect of synthetic detergents on germination of fern spores

    Energy Technology Data Exchange (ETDEWEB)

    Devi, Y.; Devi, S.

    1986-12-01

    Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.

  18. Germination of myxospores from the fruiting bodies of Myxococcus xanthus.

    OpenAIRE

    Otani, M.; Inouye, M; Inouye, S

    1995-01-01

    Germination of myxospores from fruiting bodies of Myxococcus xanthus was examined under a light microscope as well as by analyzing the incorporation of [3H]uracil into the RNA fraction. Efficient germination was observed in 0.2% Casitone containing 8 mM MgSO4 and 1 mM CaCl2 at 30 degrees C. Under this condition, spherical myxospores were converted into rod-shaped vegetative cells within 5 to 6 h. The germination was severely inhibited in the presence of 1 mM phenylmethylsulfonyl fluoride, a p...

  19. Seed germinating characteristics of 54 gramineous species in the alpine meadow on the eastern Qinghai-Tibet plateau

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The germination experiment was started on March 3,2004,and seeds were collected from July to October in 2003.We analyzed the percentage of germination,days to first germination,germination period and days to 50% germination.Among the 54 examined species,26 species exceeded 80% germination,11 species exceeded 60%-80% germination,8 exceeded 40%-0%,5 exceeded20%-40%,and 4 showed less than 20%.A principalcomponent analysis revealed that the species were distributed along two statistically independent axes,the first primarily represented the germination rate and the second represented the time of germination process.Based on scores of germination characteristics,duster analysis of the 54 gramineous species could be divided into 4 distinct groups:rapid,slow,intermediate germinating (germination percentage> 50%),and low germinating (germination percentage< 50%).The meaning of different groups to the vegetation regeneration was discussed.

  20. Effect of germination periods and hydrothermal treatments on in vitro protein and starch digestibility of germinated legumes.

    Science.gov (United States)

    Uppal, Veny; Bains, Kiran

    2012-04-01

    Germination of legumes followed by hydrothermal treatments is an effective mean of improving nutritive value of legumes. The protein content of mungbean, chickpea and cowpea increased by 9-11, 11-16 and 8-11% after germination. A significant (p ≤ 0.05) decrease in protein content was observed on pressure cooking and microwaving in all three legumes. The carbohydrates decreased by 1 to 3% during soaking and 2 to 6% during germination. A significant (p ≤ 0.05) improvement in in vitro protein digestibility (IVPD) was observed after soaking as well as after three germination periods. Germination resulted in an increase in IVPD from 15 to 25% in mungbean, 6 to 17% in chickpea and 6 to 17% in cowpea. A significant (p ≤ 0.05) increase in IVPD was observed when raw sprouts of three legumes were subjected to pressure cooking and microwaving. In vitro starch digestibility (IVSD) increased significantly (p ≤ 0.05) after germination, the percent increase being 8 to 12% in mungbean, 9 to 11% in chickpea and 10 to 13% in cowpea. The duration of germination had significant (p ≤ 0.05) effect on IVSD. A significant (p ≤ 0.05) improvement in IVSD was observed when legume sprouts were subjected to pressure cooking and microwave cooking.

  1. Germination of Croton urucurana L. seeds exposed to different storage temperatures and pre-germinative treatments

    Directory of Open Access Journals (Sweden)

    Silvana P.Q. Scalon

    2012-03-01

    Full Text Available The present work evaluated the germinability and vigor of Croton urucurana seeds. 1 Seeds were sorted by color (caramel, gray and black and were subjected to seven different pre-germination treatments followed by incubation at 20ºC, 25°C or 20/30°C. 2 Seeds were stored in cold chambers or at room temperature for up to 300 days and were subsequently incubated at 20/30ºC in a germination chamber or under greenhouse conditions. Only gray seeds showed significant germination rates. The highest first count percentages of total germination and the highest germination speed indices were observed in control seeds and in those which were treated with water or 200 mg. L-1 gibberellic acid for 12 hours. Seeds stored under refrigeration showed the highest values for all of the characteristics examined, as well as less electrical conductivity of the imbibing solution. Seedlings were more vigorous when seeds were stored for 300 days in a cold chamber. The seedlings production can be increased by incubating the seeds at alternating temperatures (20/30°C. The seeds do not need pre-germination treatments.O presente trabalho avaliou a germinação e vigor de sementes de Croton urucurana. 1 As sementes foram classificadas por cores (caramelo, cinza e preto e foram submetidas a sete diferentes tratamentos pré-germinativos seguidos de incubação a 20ºC, 25°C e 20/30°C. 2 As sementes foram armazenadas em câmaras frias ou em temperatura ambiente por até 300 dias e foram posteriormente incubadas a 20/30ºC em câmara de germinação ou em condições de estufa. Somente sementes cinza apresentaram taxas significativas de germinação. As maiores percentagens de primeira contagem de germinação total e os maiores índices de velocidade de germinação foram observados em sementes de controle e naquelas que foram tratadas com água ou 200 mg L-1 de ácido giberélico por 12 horas. Sementes armazenadas sob refrigeração apresentaram os maiores valores para

  2. Effect of germination periods and hydrothermal treatments on in vitro protein and starch digestibility of germinated legumes

    OpenAIRE

    Uppal, Veny; Bains, Kiran

    2011-01-01

    Germination of legumes followed by hydrothermal treatments is an effective mean of improving nutritive value of legumes. The protein content of mungbean, chickpea and cowpea increased by 9–11, 11–16 and 8–11% after germination. A significant (p ≤ 0.05) decrease in protein content was observed on pressure cooking and microwaving in all three legumes. The carbohydrates decreased by 1 to 3% during soaking and 2 to 6% during germination. A significant (p ≤ 0.05) improvement in in vitro protein di...

  3. Hungarian surveillance of germinal mutations. Lack of detectable increase in indicator conditions caused by germinal mutations following the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Czeizel, A. (National Inst. of Hygiene, Budapest (Hungary). Dept. of Human Genetics and Teratology)

    1989-07-01

    The Hungarian surveillance of germinal mutations is based on three indicator conditions seen in offspring, i.e., 15 sentinel anomalies, Down syndrome and component anomaly pairs of unidentified multiple congenital anomalies. It is an 'opportunistic program', because the necessary data are available from the Hungarian Congenital Malformation Registry. This system is described and the criteria of a good registry are summarized. The analysis of indicator conditions caused by germinal mutations did not reveal any measurable mutagenic effects in Hungary following the accident at the Chernobyl nuclear power plant. The pros and cons of germinal mutation surveillance are discussed. (orig.).

  4. Germination of Chenopodium Album in Response to Microwave Plasma Treatment

    Institute of Scientific and Technical Information of China (English)

    Bo(z)ena (S)ER(A); Vitězslav STRA(NA)K; Michal (S)ER(Y); Milan TICH(Y); Petr (S)PATENKA

    2008-01-01

    The seeds of Lamb's Quarters (Chenopodium album agg.) were stimulated by low-pressure discharge. The tested seeds were exposed to plasma discharge for different time durations (from 6 minutes to 48 minutes). Germination tests were performed under specified laboratory conditions during seven days in five identical and completely independent experiments. Significant differences between the control and plasma-treated seeds were observed. The treated seeds showed structural changes on the surface of the seat coat. They germinated faster and their sprout accretion on the first day of seed germination was longer. Germination rate for the untreated seeds was 15% while it increased approximately three times (max 55%) for seeds treated by plasma from 12 minutes to 48 minutes.

  5. Germination of Chenopodium Album in Response to Microwave Plasma Treatment

    Science.gov (United States)

    Será, Bozena; Stranák, Vitezslav; Serý, Michal; Tichý, Milan; Spatenka, Petr

    2008-08-01

    The seeds of Lamb's Quarters (Chenopodium album agg.) were stimulated by low-pressure discharge. The tested seeds were exposed to plasma discharge for different time durations (from 6 minutes to 48 minutes). Germination tests were performed under specified laboratory conditions during seven days in five identical and completely independent experiments. Significant differences between the control and plasma-treated seeds were observed. The treated seeds showed structural changes on the surface of the seat coat. They germinated faster and their sprout accretion on the first day of seed germination was longer. Germination rate for the untreated seeds was 15% while it increased approximately three times (max 55%) for seeds treated by plasma from 12 minutes to 48 minutes.

  6. Effect of Pretreatments on Seed Germination of Prunus mahaleb L

    National Research Council Canada - National Science Library

    Elias PIPINIS; Elias MILIOS; Olga MAVROKORDOPOULOU; Christina GKANATSIOU; Maria ASLANIDOU; Pavlos SMIRIS

    2012-01-01

    Sexual propagation of Prunus mahaleb is difficult due to seed dormancy. To overcome dormancy and maximize germination, various pretreatments have been applied, including stratification (warm and cold), gibberellic acid (GA3...

  7. Autotoxicity of chard and its allelopathic potentiality on germination ...

    African Journals Online (AJOL)

    SERVER

    2008-04-03

    Apr 3, 2008 ... weed management, weeds are still responsible for the ... incidence of resistance to herbicides in weeds (Valverde .... their metabolic changes during germination in response ..... Freedman and Company, San Francisco.

  8. 7 CFR 201.53 - Source of seeds for germination.

    Science.gov (United States)

    2010-01-01

    ... separation of the kind, variety, or type considered pure seed and shall be counted without discrimination as to size or appearance. (b) When only a germination test is required and the pure seed is estimated...

  9. Effects of tallowtree seed coat on seed germination

    Institute of Scientific and Technical Information of China (English)

    LI Shu-xian; GU Hong-biao; MAO Yan; YIN Tong-ming; GAO Han-dong

    2012-01-01

    We measured physiological parameters including water uptake,in-vitro embryo germination ratio,and seed coat structure observed by scanning electron microscopy (SEM) to explore the influence of seed coat on the germination of seeds of tallow tree (Sapium sebiferum (Linn) Roxb.).Tallow tree seeds had good water permeability.We found that germination of cabbage seeds was inhibited when cabbage seeds were soaked in extracted solutions from tallow tree seed coat.Seed coat structure at the side of the radicle appeared to be a barrier to seed germination.We tested methods to break tallow tree seed dormancy.Dormancy of tallow tree seeds was overcome by soaking the seeds in 500 mg·L-1 or 1000 mg·L-1 GA3,followed by 100 days of cold stratification.

  10. Germination at low osmotic potential as a selection criteria for ...

    African Journals Online (AJOL)

    user

    2014-01-08

    Jan 8, 2014 ... the potential to be used as a vigor test in sweet corn. Key words: Osmotic potential, germination, polyethylene glycol, corn, proline ..... J. Food Agric. ... accumulation of genetically modified potatoes (Solanum tuberosum.

  11. The plasma membrane proteome of germinating barley embryos

    DEFF Research Database (Denmark)

    Hynek, Radovan; Svensson, Birte; Jensen, O.N.

    2009-01-01

    was used to reduce soluble protein contamination and enrich for hydrophobic proteins. Sixty-one proteins in 14 SDS-PAGE bands were identified by LC-MS/MS and database searches. The identifications provide new insight into the plasma membrane functions in seed germination.......Cereal seed germination involves a complex coordination between different seed tissues. Plasma membranes must play crucial roles in coordination and execution of germination; however, very little is known about seed plasma membrane proteomes due to limited tissue amounts combined...... with amphiphilicity and low abundance of membrane proteins. A fraction enriched in plasma membranes was prepared from embryos dissected from 18 h germinated barley seeds using aqueous two-phase partitioning. Reversed-phase chromatography on C-4 resin performed in micro-spin columns with stepwise elution by 2-propanol...

  12. In vitro spore germination and gametophytic growth development of ...

    African Journals Online (AJOL)

    SAM

    2014-06-04

    Jun 4, 2014 ... Maximum spore germination rates (84%) were observed in. 70 g/L of sucrose and .... two weeks and gametophyte growth rates (length, width of ..... Smith AR, Pryer KM, Schuettpelz E, Korall P, Schneider H, Wolf PG. (2006).

  13. Seed germination in a southern Australian temperate seagrass

    Science.gov (United States)

    Jarvis, Jessie C.; Sherman, Craig D.H.; York, Paul H.; Smith, Timothy M.

    2017-01-01

    In a series of experiments, seeds from a temperate seagrass species, Zostera nigricaulis collected in Port Phillip Bay, Victoria, Australia were exposed to a range of salinities (20 PSU pulse/no pulse, 25 PSU, 30 PSU, 35 PSU), temperatures (13 °C, 17 °C, 22 °C), burial depths (0 cm, 1 cm, 2 cm) and site specific sediment characteristics (fine, medium, coarse) to quantify their impacts on germination rate and maximum overall germination. In southern Australia the seagrass Z. nigricaulis is a common subtidal species; however, little is known about the factors that affect seed germination which is a potential limiting factor in meadow resilience to natural and anthropogenic disturbances. Overall seed germination was low (large scale rainfall events. As a result, these populations may be particularly susceptible to disturbance with only a seasonally limited capacity for recovery.

  14. Lipoxygenase Activity Accelerates Programmed Spore Germination in Aspergillus fumigatus

    Directory of Open Access Journals (Sweden)

    Gregory J. Fischer

    2017-05-01

    Full Text Available The opportunistic human pathogen Aspergillus fumigatus initiates invasive growth through a programmed germination process that progresses from dormant spore to swollen spore (SS to germling (GL and ultimately invasive hyphal growth. We find a lipoxygenase with considerable homology to human Alox5 and Alox15, LoxB, that impacts the transitions of programmed spore germination. Overexpression of loxB (OE::loxB increases germination with rapid advance to the GL stage. However, deletion of loxB (ΔloxB or its signal peptide only delays progression to the SS stage in the presence of arachidonic acid (AA; no delay is observed in minimal media. This delay is remediated by the addition of the oxygenated AA oxylipin 5-hydroxyeicosatetraenoic acid (5-HETE that is a product of human Alox5. We propose that A. fumigatus acquisition of LoxB (found in few fungi enhances germination rates in polyunsaturated fatty acid-rich environments.

  15. A possible role of chemotaxis in germinal center formation

    CERN Document Server

    Beyer, T; Soff, G; Beyer, Tilo; Meyer-Hermann, Michael; Soff, Gerhard

    2002-01-01

    During the germinal center reaction a characteristic morphology is developed. In the framework of a recently developed space-time-model for the germinal center a mechanism for the formation of dark and light zones has been proposed. The mechanism is based on a diffusing differentiation signal which is secerned by follicular dendritic cells. Here, we investigate a possible influence of recently found chemokines for the germinal center formation in the framework of a single-cell-based stochastic and discrete three-dimensional model. We will also consider alternative possible chemotactic pathways that may play a role for the development of both zones. Our results suggest that the centrocyte motility resulting from a follicular dendritic cell-derived chemokine has to exceed a lower limit to allow the separation of centroblasts and centrocytes. In contrast to light microscopy the dark zone is ring shaped. This suggests that FDC-derived chemoattractants alone cannot explain the typical germinal center morphology.

  16. The role of seed priming in improving seed germination and ...

    African Journals Online (AJOL)

    win7

    2013-11-13

    Nov 13, 2013 ... Salinity is considered as a major abiotic stress affecting germination, seedling growth and crop ... of the metabolic processes involved in the early phases ..... Church Regional Senior Consultant on Environment and Natural.

  17. Seed and Germination Characteristics of 20 Amazonian Liana Species

    Science.gov (United States)

    Roeder, Mareike; Ferraz, Isolde D. K.; Hölscher, Dirk

    2013-01-01

    Lianas are an important component of tropical forests, and may reach their highest densities in disturbed areas. However, information on seed and germination characteristics is scarce. Twenty Amazon liana species were screened for their germination characteristics, including light dependence, tolerance of desiccation and of alternating temperatures; these characteristics are considered important for the germination success in areas with relatively open canopies. Between 31–1,420 seeds per species were available, as 15 species seeds came from one mother plant. We studied seed biometry and conducted germination trials with fresh seeds (12 h light daily, or dark) and desiccated seeds at 25 °C. Germination at alternating temperatures (20/30 °C, 15/35 °C) was analyzed for nine species. Of the 20 species, eight species with the largest seeds had desiccation sensitive seeds; this is the first record for species of four genera and one family, where only desiccation tolerant seeds are otherwise recorded. Light-dependent germination was found in three species (0.01–0.015 g) and is the first record for two; however, results were based on seeds from one plant per species. Alternating temperatures of 15/35 °C decreased final germination of four out of nine species, and response to 20/30 °C cycles varied compared to constant 25 °C. Seed and germination characteristics of the species ranged from pioneer to climax traits indicating that establishment of lianas from seeds may be confined to species specific niches. PMID:27137363

  18. Vermicompost enhances germination of the maritime pine (Pinus pinaster Ait.)

    OpenAIRE

    Lazcano, Cristina; Sampedro, Luis; Zas Arregui, Rafael; Domínguez, Jorge

    2010-01-01

    We investigated the effect of vermicompost on the germination and early development of six different progenies of the maritime pine (Pinus pinaster Ait.). We compared the effects of incorporating solid vermicompost into the potting media to those of vermicompost water extract to asses the extent of not physically-mediated positive effects. The incorporation of vermicompost in the growing media of maritime pine increased germination by 16%, and particularly, addition of vermicom...

  19. Effect of Estrogen and Progeterone on seed germination

    Directory of Open Access Journals (Sweden)

    Nirmala

    Full Text Available Early pregnancy detection in dairy cattle is an integral part of a successful animal husbandry practice. A simple seed germination technique (Punyakoti test comprises observation of differential seed germination response of wheat seeds to diluted fresh urine samples as reflected by significant inhibition of germination percentage in pregnant cow urine when compared to non pregnant cow urine. Hormone metabolites excreted through urine might affect the seed germination in pregnant cow urine. In the present study an attempt was made to test the effect of hormones (in their natural forms at different concentrations of estrogen (17-ß estradiol and progesterone on wheat and green gram germination. Stock solutions of estrogen and progesterone were prepared in alcohol (1mg/ml and serial dilutions made using distilled water to get the concentrations of T1=10, T2=1, T3=0.1 and T4=0.01 μg/ml respectively in treatment groups. About 15 seeds each of wheat and green gram were taken in sterile Petri dishes into which 15ml of each test preparation was poured. The treatments were compared with distilled water and alcohol controls. The study was conducted for a period of five days during which seed germination was observed after 48 hrs and shoot lengths were also measured by the end of study. The average seed germination and shoot length in treatment groups did not vary significantly (P>0.05 when compared with that of control groups. Thus from the present study, it can be concluded that estrogen and progesterone in their natural form will not affect seed germination and shoot length. [Veterinary World 2008; 1(8.000: 241-242

  20. Seed Germination of Some Crocus Species of Western Anatolia

    OpenAIRE

    HASPOLAT, Gülden; ÖZZAMBAK, M. Ercan; ŞIK, Levent

    2013-01-01

    In this study, germination studies were carried out on some Crocus species such as Crocus olivieri ssp. balansae, Crocus chrysanthus, Crocus baytopiorum, Crocus pallasii ssp. pallasii spreading at western Anatolia. Seed viability was determined by using tetrazolium test. Testa, endosperm, embryo bed of seeds were examined at stereo binocular. The pretreatments for germination were; waiting seeds in moist sand at 5oC for 4 weeks, keeping seeds for 24 hours in water and in 200400 mg/l GA3 solut...

  1. Ribosomal ribonucleic acid maturation during bacterial spore germination.

    Science.gov (United States)

    Bleyman, M; Woese, C

    1969-01-01

    All the ribosomal ribonucleic acid made during the early stages of germination of spores of Bacillus subtilis is of the "precursor" type, i.e., that type appearing in the incomplete forms of the ribosome. Shortly before the onset of deoxyribonucleic acid synthesis in germination, this precursor ribonucleic acid changed to the mature ribosomal ribonucleic acid characteristic of the 30S and 50S ribosomal subunits.

  2. Cortex Peptidoglycan Lytic Activity in Germinating Bacillus anthracis Spores▿

    OpenAIRE

    2008-01-01

    Bacterial endospore dormancy and resistance properties depend on the relative dehydration of the spore core, which is maintained by the spore membrane and its surrounding cortex peptidoglycan wall. During spore germination, the cortex peptidoglycan is rapidly hydrolyzed by lytic enzymes packaged into the dormant spore. The peptidoglycan structures in both dormant and germinating Bacillus anthracis Sterne spores were analyzed. The B. anthracis dormant spore peptidoglycan was similar to that fo...

  3. Seed and germination characteristics of wild Onobrychis taxa in Turkey

    OpenAIRE

    AVCI, Süleyman; KAYA, Mehmet Demir

    2013-01-01

    Turkey is of great importance for the biodiversity of genus Onobrychis Adans. and hosts 55 species that are adapted to dry and poor environments. This study was conducted to evaluate 35 Onobrychis taxa in terms of 1000-seed weight, germination percentage, mean germination time, and hard and swollen seeds and to determine the suitability of mechanical scarification for dormancy breaking in species with hard or impermeable seed coats. Seed dormancy was detected in 19 of the investigated species...

  4. The germinal center antibody response in health and disease

    OpenAIRE

    DeFranco, Anthony L.

    2016-01-01

    The germinal center response is the delayed but sustained phase of the antibody response that is responsible for producing high-affinity antibodies of the IgG, IgA and/or IgE isotypes. B cells in the germinal center undergo re-iterative cycles of somatic hypermutation of immunoglobulin gene variable regions, clonal expansion, and Darwinian selection for cells expressing higher-affinity antibody variants. Alternatively, selected B cells can terminally differentiate into long-lived plasma cells...

  5. Seed and Germination Characteristics of 20 Amazonian Liana Species

    Directory of Open Access Journals (Sweden)

    Mareike Roeder

    2013-01-01

    Full Text Available Lianas are an important component of tropical forests, and may reach their highest densities in disturbed areas. However, information on seed and germination characteristics is scarce. Twenty Amazon liana species were screened for their germination characteristics, including light dependence, tolerance of desiccation and of alternating temperatures; these characteristics are considered important for the germination success in areas with relatively open canopies. Between 31–1,420 seeds per species were available, as 15 species seeds came from one mother plant. We studied seed biometry and conducted germination trials with fresh seeds (12 h light daily, or dark and desiccated seeds at 25 °C. Germination at alternating temperatures (20/30 °C, 15/35 °C was analyzed for nine species. Of the 20 species, eight species with the largest seeds had desiccation sensitive seeds; this is the first record for species of four genera and one family, where only desiccation tolerant seeds are otherwise recorded. Light-dependent germination was found in three species (0.01–0.015 g and is the first record for two; however, results were based on seeds from one plant per species. Alternating temperatures of 15/35 °C decreased final germination of four out of nine species, and response to 20/30 °C cycles varied compared to constant 25 °C. Seed and germination characteristics of the species ranged from pioneer to climax traits indicating that establishment of lianas from seeds may be confined to species specific niches.

  6. Enhanced germination and gravitropism of soybean in a hypogeomagnetic field

    Science.gov (United States)

    Mo, Weichuan

    For the future manned space exploration, the duration of the missions would significantly in-crease. Investigating plant growth and development under the space environmental conditions is of essential importance for the food supply projects for the astronauts. Hypogeomagnetic field (HGMF), namely, extremely low magnetic field, is one of the main characters of the space environment. Germination is the first vital step of plant growth and development, which determines the final yield of plants. The effect of HGMF on plant growth, especially early ger-mination, still remains open. In this study, we established a hypogeomagnetic field (HGMF) incubation system, the remnant magnetic field inside no more than 250 nT. Soybean seeds were incubated at 25 in HGMF, and the very beginning of soybean germination, from water ab-sorbance of cotyledon to radicle emergence, was examined within 24 h. Our results showed that the germination ratio and weight ratio of emerged soybean radicles were markedly increased during germination in HGMF. Furthermore, the tropism angle of emerged radicle with gravity in HGMF was statistically smaller than that in GMF when the radicle direction was placed opposite to gravity before germination. These results indicate that the germination and gravit-ropism of soybean is enhanced in a hypogeomagnetic environment, This is a new finding about the early seed germination in such a low environmental magnetic field which is comparable to the magnetic field of Lunar Swirls on the Moon (a few hundred nT), and it might provide new perspectives on the space science researches concerning plant growth and food supply.

  7. Pollen germination in vitro of Mexican Crataegus spp.

    Directory of Open Access Journals (Sweden)

    M. W. Borys

    2014-01-01

    Full Text Available The germination of pollen in vitro of 42 selections of Crataegus belonging to the cultivated group (C. pubescens (H.B.K. Steud. = C. mexicana Moc. et Sessé and wild group (probably C. nelsoni Eggleston was evaluated. The anthers size (length and width of each selection was also determined. Both attributes were determined by using undehisced anthers of flowers of the spring flowering period (dry season. The percent of germinated pollen varied from 82.4 to 94.2%, depending upon the selection; both groups of selections gave similar values of germination. The 45.83% of selections of the wild group gave from 88 to 90% of germinated pollen. The selections of cultivated group have been characterized by a wide range of pollen germination. The anther size - length and width - depended upon the selection. The plants of the cultivated group showed a larger size more frequently than those of the wild group. No correlation was found between pollen germination and anthers dimensions. The results were discussed in relation to productivity of fruits trees of the Mexican representatives included in the germplasm collection.

  8. TIME REDUCTION FOR SURINAM GRASS SEED GERMINATION TEST

    Directory of Open Access Journals (Sweden)

    Camila de Aquino Tomaz

    2015-10-01

    Full Text Available ABSTRACTThe period for the germination test of Surinam grass seeds established by the Rules for Seeds Testing is 28 days, considered too lengthy by producers, venders, and seed analysis laboratories. So, the objective of this research was to evaluate the possibility of reducing the time for the germination test of Surinam grass seeds and to establish a method for dormancy breaking and the ideal temperature. Ten seed lots were submitted to the following treatments to overcome seed dormancy: control; substrate moistening with 0.2% KNO3; and scarification with sulfuric acid (98% 36 N for 15 minutes. After the treatments, the lots were submitted to seed water content, germination and tetrazolium tests. During the germination test, conducted with four replicates of 100 seeds per treatment for 28 days, two conditions of alternating temperatures (20-35 °C and 15-35 °C with 8 hours of light were tested. Attempting to determine the test end date, daily counts of the number of normal seedlings were made and for each lot, treatment, and temperature, a growth curve for the evaluation of germination was adjusted. The segmented regression model parameter estimations were calculated for each treatment. The germination test of Braquiaria decumbensseeds may be evaluated in 12 days after sowing using alternating temperatures of 20-35 °C and without any treatment to overcome dormancy.

  9. Polymer coating, germination and vigor of broccoli seeds

    Directory of Open Access Journals (Sweden)

    Almeida Celina de

    2005-01-01

    Full Text Available Brassica oleracea var italica occupies a special place in the internal and external market of vegetables seeds. Vegetables producers demand seeds with high degree of purity, germination and vigor, since seeds' quality is the basis for the success of the production. In this work, broccoli seeds were coated in a spouted bed, by an aqueous suspension of hidroxy-ethyl-cellulose. Effects of the operating variables: spouting air temperature, atomizing air pressure and coating suspension flow rate over the dependent variables: seeds germination, seeds accelerated aging and the speed of seeds germination in soil, were investigated in a factorial scheme trial. The maximum processing time was 120 min. A totally randomized experiment evaluated and compared seeds germination and vigor of the coated and non-coated seeds. There was no identifiable, pronounced difference on germination of coated and non-coated seeds, accelerated aging of seeds, and speed of seeds germination in the soil. Coating with hidroxy-ethyl-cellulose in the spouted bed did not alter broccoli seeds physiologic quality. The surface of coated seeds presented satisfactory distribution and spreading of the polymer film, uniform and individual coating and homogeneous aspect.

  10. Improving Seed Germination and Peanut Yields by Cold Plasma Treatment

    Science.gov (United States)

    Li, Ling; Li, Jiangang; Shen, Minchong; Hou, Jinfeng; Shao, Hanliang; Dong, Yuanhua; Jiang, Jiafeng

    2016-10-01

    This study explored the effects of cold plasma treatment on seed germination, plant growth, and peanut yield. Cold plasma treatment improved germination and seedling growth, and the 120 W treatment produced the best effect. Germination potential and germination rate were markedly raised by 150% and 21%, respectively. Germination was accelerated and the uniformity of emergence improved. The apparent contact angle was decreased by 53%. Seedling shoot and root dry weights increased by 11% and 9%. Leaf area, leaf thickness, leaf nitrogen concentration, chlorophyll contents, and dry weight at the fruiting stage, together with plant height, stem diameter, and root dry weight at the mature stage were all markedly raised by the cold plasma treatment. The cold plasma treatment enhanced yield components, such as branch numbers per plant, pod numbers per plant, and 100 pod weights by 8%, 13%, and 9%, respectively, compared to the control. Furthermore, the yield improved by 10%. These results suggested that cold plasma treatment improved germination, plant growth, and yield, which might be due to the cold plasma increasing the leaf area, nitrogen concentrations, and chlorophyll contents. supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China (No. 2012BAD05B04), National Natural Science Foundation of China (No. 41201241), “Strategic Priority Research Program” of the Chinese Academy of Sciences (No. XDB15030301) and Jiangsu Province Science and Technology Support Program (No. BE2013452)

  11. YY1 Is Required for Germinal Center B Cell Development.

    Science.gov (United States)

    Banerjee, Anupam; Sindhava, Vishal; Vuyyuru, Raja; Jha, Vibha; Hodewadekar, Suchita; Manser, Tim; Atchison, Michael L

    2016-01-01

    YY1 has been implicated as a master regulator of germinal center B cell development as YY1 binding sites are frequently present in promoters of germinal center-expressed genes. YY1 is known to be important for other stages of B cell development including the pro-B and pre-B cells stages. To determine if YY1 plays a critical role in germinal center development, we evaluated YY1 expression during B cell development, and used a YY1 conditional knock-out approach for deletion of YY1 in germinal center B cells (CRE driven by the immunoglobulin heavy chain γ1 switch region promoter; γ1-CRE). We found that YY1 is most highly expressed in germinal center B cells and is increased 3 fold in splenic B cells activated by treatment with anti-IgM and anti-CD40. In addition, deletion of the yy1 gene by action of γ1-CRE recombinase resulted in significant loss of GC cells in both un-immunized and immunized contexts with corresponding loss of serum IgG1. Our results show a crucial role for YY1 in the germinal center reaction.

  12. Effect of zinc sulfate fortification in germinated brown rice on seed zinc concentration, bioavailability, and seed germination.

    Science.gov (United States)

    Wei, Yanyan; Shohag, M J I; Wang, Yuyan; Lu, Lingli; Wu, Chunyong; Yang, Xiaoe

    2012-02-22

    Rice is the staple food for more than half of the world's population and, hence, the main source of a vital micronutrient, zinc (Zn). Unfortunately, the bioavailability of Zn from rice is very low not only due to low content but also due to the presence of some antinutrients such as phytic acid. We investigated the effect of germination and Zn fortification treatment on Zn bioavailability of brown rice from three widely grown cultivars using the Caco-2 cell model to find a suitable fortification level for producing germinated brown rice. The results of this study showed that Zn content in brown rice increased significantly (p 0.05) on germination percentage of rice was observed when the Zn supply was lower than 150 mg/L. Zn fortification during the germination process has a significant impact on the Zn content and finally Zn bioavailability. These findings may result from the lower molar ratio of phytic acid to Zn and higher Zn content in Zn fortified germinated brown rice, leading to more bioavailable Zn. Likewise, a significant difference (p world population, we recommend germinated brown rice fortified with 100 mg/L ZnSO(4) as a suitable concentration to use in the germination process, which contains high Zn concentration and Zn bioavailability. In the current study, the cultivar Bing91185 fortified with Zn through the germination process contained a high amount as well as bioavailable Zn, which was identified as the most promising cultivar for further evaluation to determine its efficiency as an improved source of Zn for target populations.

  13. EFFECTS OF DIFFERENT PRE-TREATMENTS AND GERMINATION MEDIA ON SEED GERMINATION AND SEEDLING GROWTH OF Parkia timoriana (DC. Merr

    Directory of Open Access Journals (Sweden)

    Uttam Thangjam

    2017-02-01

    Full Text Available Parkia timoriana (DC. Merr. is one of the lesser known multipurpose leguminous tree species found in North East India. Like many other legumes this species too have hard coated seeds which prevent seed germination and thus there is a need to investigate the most appropriate method to break its dormancy. Six pre treatments (tap water, gibberellic acid (GA3 @ 500 ppm, stratification, sulphuric acid @ 98%, boiling water and nicking and two media (top of paper (TOP and sand were use to evaluate seed germination traits and initial growth parameters of the seedling of this tree species. Along with these pre treatments, seeds sown in TOP media and tap water gave maximum seed germination (72% and it was followed by seeds exposed to GA₃ for 24 hours (64% while the least seed germination was reported in seeds treated with sulphuric acid (H2SO4 for 5 minutes. Least germination time (Mean Germination Time was reported from the seeds treated with H2SO4 for 1 minute while maximum was reported from the boiling water treatments. Under sand medium, highest germination was reported in control (66.67 % and it was followed by boiling water treatment (58.33% and minimum (16.67% in seeds treated with H2SO4 for 5 minute. Seed treated with H2SO4 for 5 minutes took minimum germination time too. Interestingly, irrespective to the media, all the seedling growth parameters showed maximum response towards hormonal (GA3 treatment and minimum towards H2SO4 treatment. Significant correlations were found between all the seedling growth parameters except for collar diameter and root-shoot ratio

  14. Aminopeptidase activity from germinated jojoba cotyledons.

    Science.gov (United States)

    Johnson, R; Storey, R

    1985-11-01

    One major and two minor aminopeptidase activities from germinated jojoba (Simmondsia chinensis) cotyledon extracts were separated by ammonium sulfate precipitation and chromatofocusing. None of the activities were inhibited by 1,10 phenanthroline.The major aminopeptidase, purified 260-fold, showed a pH optimum of 6.9 with leucine-p-nitroanilide as substrate, a molecular weight estimated at 14,200 by electrophoretic analysis, and an isoelectric point of 4.5 according to the chromatofocusing pattern. Activity was inhibited by p-chloromercuribenzoate, slightly stimulated by 1,10 phenanthroline and 2-mercaptoethanol, and not influenced by Mg(2+) or diethyl pyrocarbonate. Inhibition by p-chloromercuribenzoate was prevented by the presence of cysteine in the assay. Leucine-p-nitroanilide and leucine-beta-naphthylamide were the most rapidly hydrolyzed of 11 carboxy-terminal end blocked synthetic substrates tested. No activity on endopeptidase or carboxypeptidase specific substrates was detected. The major aminopeptidase showed activity on a saline soluble, jojoba seed protein preparation and we suggest a possible physiological role for the enzyme in the concerted degradation of globulin reserve proteins during cotyledon senescence.

  15. Environmental Factors that Interfere in the Germination

    Directory of Open Access Journals (Sweden)

    Lisiane de Souza

    2014-12-01

    Full Text Available This paper refers to the application of experiments with sixth graders of elementary school, aiming motivation, skills development focused on observation, interpersonal relationships in teams, related to the various forms of language skills, as well to identify and resume misconceptions about the external (environmental factors required for seed germination, in order that the contents developed this year refer to the study of the earth, soil, water and air, among others, and that many students do not understand all the concepts and the importance of these factors for the existence of living beings. The experiments were organized in two stages, first to observe the influence of soil and another moment to observe the interference of water, air and light. The temperature impractical activities were conducted, however, during the observation period (three weeks experiments remained in a controlled environment in the science laboratory. For the experiments we used materials easily found in commerce, some recycled; students were organized into six teams, which improved the data collection, the maintenance of the experiments, the calculations of the percentages, and the producing of report. Many of these contents had not yet been studied in other disciplines, but were developed in the discipline of science, respecting prior knowledge and cognitive abilities. The use of experiments was effective for the construction of new knowledge and to develop skills necessary to start the search.

  16. Maternal Germinal Trisomy 21 in Down Syndrome

    Directory of Open Access Journals (Sweden)

    Maj A. Hultén

    2014-01-01

    Full Text Available It has now been over 50 years since it was discovered that Down syndrome is caused by an extra chromosome 21, i.e., trisomy 21. In the interim, it has become clear that in the majority of cases, the extra chromosome is inherited from the mother, and there is, in this respect, a strong maternal age effect. Numerous investigations have been devoted to clarifying the underlying mechanism, most recently suggesting that this situation is exceedingly complex, involving both biological and environmental factors. On the other hand, it has also been proposed that germinal trisomy 21 mosaicism, arising during the very early stages of maternal oogenesis with accumulation of trisomy 21 germ cells during subsequent development, may be the main predisposing factor. We present data here on the incidence of trisomy 21 mosaicism in a cohort of normal fetal ovarian samples, indicating that an accumulation of trisomy 21 germ cells does indeed take place during fetal oogenesis, i.e., from the first to the second trimester of pregnancy. We presume that this accumulation of trisomy 21 (T21 cells is caused by their delay in maturation and lagging behind the normal cells. We further presume that this trend continues during the third trimester of pregnancy and postnatally, up until ovulation, thereby explaining the maternal age effect in Down syndrome.

  17. La organización germinal

    Directory of Open Access Journals (Sweden)

    Xavier Soca Filella

    2013-08-01

    Full Text Available Las vicisitudes de estos últimos años en las economías occidentales, y sobre todo en las del arco mediterráneo, han sumido las empresas en un profundo callejón sin salida, dónde tras efectuar reducciones drásticas en sus estructuras ahora ven mermadas sus posibilidades de crecimiento. Surge el interrogante de qué tipo de crecimiento perseguimos y qué organización precisamos para conseguirlo. Vislumbramos a partir de lo acaecido en los últimos dos lustros que las organizaciones preferirán moverse dentro de unos patrones de crecimientos sostenibles, en lugar de las alocadas carreras de inicios de siglo. Este crecimiento sostenible comportará decidir que formas de organización permitirán gestionar mejor este crecimiento. Dentro del abanico de las posibilidades, planteo un tipo de organización en constante cambio que facilite la adaptación a los diversos tipos de mercados que puedan ir surgiendo en el futuro: LA ORGANIZACIÓN GERMINAL.

  18. Temperature in the seeds germination of pitaya genotypes

    Directory of Open Access Journals (Sweden)

    Alessandro Borini Lone

    2014-09-01

    Full Text Available The optimum temperature for germination of cacti vary with the species. With this work, we aimed to evaluate the seeds germination of pitaya genotypes under different temperatures. The used genotypes were: Hylocereus undatus (PB, H. polyrhizus (PV, Selenicereus megalanthus (PA, H. undatus x H. costaricensis (PH1 and H. costaricensis x H. undatus (PH2. For each genotype we used four replicates of 50 seeds, in a completely randomized design. The sowing was carried out on blotter paper in boxes type Gerbox ®, maintained at temperatures of 15, 20, 25, 30 and 35 oC constant and 15-25, 20-30 and 25-35 oC alternating with photoperiod 12 hours. The test lasted 30 days which were appraised the germination percentage, the germination speed index and the average time of germination. For seeds germination of PB, the result obtained in the temperature of 25 oC didn’t differ of the obtained to 30 and 20-30 oC, however it was superior to the others temperatures. In PV, the result at 25 oC didn’t differ of the obtained to 20 and 30 oC, being superior to the results of the others temperatures. For PA, the best result was obtained to 25 oC. In PH1, the temperatures of 25, 30 and 20-30 oC presented superiors results to the others. For PH2, the result obtained in 15-25oC didn’t differ of the obtained at 25 oC, however it was superior to the others temperatures. The constants temperatures of 25 and 30 °C and alternating 20-30 °C are suitable for germination of H. undatus and for the hybrid H. undatus x H. costaricensis. For H. polyrhizus, constant temperatures of 20, 25 to 30 °C are suitable for seed germination. The constant temperature of 25 °C is the most suitable for the germination of S. megalanthus. For the hybrid H. costaricensis x H. undatus, constant temperature of 25 °C and alternating 15-25°C are suitable for seed germination.

  19. Seed priming to alleviate salinity stress in germinating seeds.

    Science.gov (United States)

    Ibrahim, Ehab A

    2016-03-15

    Salinity is one of the major abiotic stresses that affect crop production in arid and semiarid areas. Seed germination and seedling growth are the stages most sensitive to salinity. Salt stress causes adverse physiological and biochemical changes in germinating seeds. It can affect the seed germination and stand establishment through osmotic stress, ion-specific effects and oxidative stress. The salinity delays or prevents the seed germination through various factors, such as a reduction in water availability, changes in the mobilization of stored reserves and affecting the structural organization of proteins. Various techniques can improve emergence and stand establishment under salt conditions. One of the most frequently utilized is seed priming. The process of seed priming involves prior exposure to an abiotic stress, making a seed more resistant to future exposure. Seed priming stimulates the pre-germination metabolic processes and makes the seed ready for radicle protrusion. It increases the antioxidant system activity and the repair of membranes. These changes promote seed vigor during germination and emergence under salinity stress. The aim of this paper is to review the recent literature on the response of plants to seed priming under salinity stress. The mechanism of the effect of salinity on seed germination is discussed and the seed priming process is summarized. Physiological, biochemical and molecular changes induced by priming that lead to seed enhancement are covered. Plants' responses to some priming agents under salinity stress are reported based on the best available data. For a great number of crops, little information exists and further research is needed.

  20. The type of seeder cells determines the efficiency of germinal center reactions

    CERN Document Server

    Meyer-Hermann, M; Meyer-Hermann, Michael; Beyer, Tilo

    2002-01-01

    We discuss the origin of two classes of germinal centers that have been observed during humoral immune responses: Some germinal centers develop very well and give rise to a large number of high affinity antibody producing plasma cells. Other germinal center reaction are very weak and the output production is practically absent. We propose an explanation for this nearly all-or-none behavior of germinal center reactions: The affinity of the seeder B-cells to the antigen is the critical parameter that determines the fate of the germinal center reaction. This hypothesis is verified in the framework of a space-time simulation of germinal center reactions.

  1. Defects in germinal center selection in SLE

    Directory of Open Access Journals (Sweden)

    Megan eWoods

    2015-08-01

    Full Text Available Germinal centers (GCs are the primary site at which clonal expansion and affinity maturation of B cells occurs. B cells encounter antigen and receive T cell help in the GC light zone (LZ and then migrate to the dark zone where they proliferate and undergo somatic mutation before cycling back to the LZ for further rounds of selection. Tolerance to autoantigens is frequently lost de novo as GC B cells undergo class switching and somatic mutation. This loss of tolerance is regulated by a variety of mechanisms including cell death, failure to compete for T cell help and failure to differentiate into effector cells. Systemic Lupus Erythematosus (SLE is characterized by loss of tolerance to nucleic acid antigens. While defects in tolerance occur in the naïve repertoire of SLE patients, pathogenic autoantibodies also arise in the GC as a result of failure to exclude autoreactive B cells from the GC and by somatic mutation from non-autoreactive precursors. Several B cell defects contribute to the loss of GC tolerance in SLE, including polymorphisms of genes that regulate BCR signaling, excess TLR7 signaling, defects in FcRIIB expression or defects of B cell apoptosis. Extrinsic soluble factors such as Type1 IFN or an imbalance between the number of TFH cells and regulatory T cells in the GC can also alter B cell negative selection. Finally, defects in macrophage clearance of apoptotic debris within the GC result in BCR mediated internalization of nucleic acid containing material and stimulation of autoantibody production by endosomal TLR driven mechanisms.

  2. INFLUENCE OF pH AND TEMPERATURE ON GERMINATION ENERGY, GERMINATION, ROOT AND SEEDLINGS HYPOCOTIL LENGTH OF VARIOUS ALFALFA CULTIVARS (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Gordana Bukvić

    2008-07-01

    Full Text Available The traits of germination energy, seed germination, as well as root and hypocotyls length of domestic alfalfa cultivars (Slavonka, Stela, Vuka were investigated in a climate chamber. The experiment was set up at two pH levels of water solution (4.00 and 6.00 and temperature levels of 10°C and 20°C using rolled filter paper method. Significant difference between cultivars (p=0.01, p=0.05 was determined for germination energy, seed germination and hypocotyls length. Cultivar Slavonka had the highest average values for germination energy and seed germination, and the lowest for hypocotyls length. Cultivar Vuka had the lowest germination energy (but with the same germination as Stela and the longest hypocotyls. Seed germination as well as root and hypocotyl length significantly depended (p=0.01 on pH of water solution. The higher average values of all traits were found at pH 4.00, except for germination energy. Temperature also significantly affected on all investigated traits (p=0.01, whilst the higher values were attained at higher temperature. Interactions cultivar x pH and cultivar x temperature were significant (p=0.01 for all traits, while pH x temperature interaction was not significant only for seed germination.

  3. Windows of opportunity for germination of riparian species after restoring water level fluctuations: a field experiment with controlled seed banks

    NARCIS (Netherlands)

    Sarneel, J.M.; Janssen, R.H.; Rip, W.J.; Bender, I.; Bakker, E.S.

    2014-01-01

    Restoration activities aiming at increasing vegetation diversity often try to stimulate both dispersal and germination. In wetlands, dispersal and germination are coupled as water and water level fluctuations (WLF) simultaneously influence seed transport and germination conditions (soil moisture). W

  4. Windows of opportunity for germination of riparian species after restoring water level fluctuations : a field experiment with controlled seed banks

    NARCIS (Netherlands)

    Sarneel, Judith M.; Janssen, Roel H.; Rip, Winnie J.; Bender, Irene M. A.; Bakker, Elisabeth S.

    2014-01-01

    1. Restoration activities aiming at increasing vegetation diversity often try to stimulate both dispersal and germination. In wetlands, dispersal and germination are coupled as water and water level fluctuations (WLF) simultaneously influence seed transport and germination conditions (soil moisture)

  5. Germinative potential of encrusted seed of tropical forage species

    Directory of Open Access Journals (Sweden)

    José Rafael de Souza

    Full Text Available ABSTRACT: Brazil is the largest producer, consumer and exporter of seeds of forage species, thus the adoption of new technologies for expansion and maintenance of this market is of great importance. The aim of this work was to evaluate encrustation effect on germination potential in seeds of Brachiaria sp. species. The experiment was carried out in Biofabrica laboratory from June to August 2014, in Universidade Estadual do Sudoeste da Bahia, Vitória da Conquista-BA. The experimental design was completely randomized, in a factorial scheme 6x2, with two treatments (with and without coating and four replications. For germination quality of seeds were evaluated germination and vigor (emergence, emergence speed index, total length of seedling, shoot and root. The encrustation affected positively the germination of seeds in all species tested and encrustation did not affect the total length, shoot and root of the seedlings. Coating after chemical scarification is an alternative to improve germination of the seeds of tropical forage species.

  6. Effects of acidity on tree pollen germination and tube growth

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, J.S.; Van Rye, D.M.; Lassoie, J.P.

    1985-01-01

    Several studies have indicated that pollen germination and tube growth are adversely affected by air pollutants. Pollutants may inhibit the function of pollen by reducing the number of pollen grains which germinate, by reducing the maximum length to which the pollen tubes grow, or by interfering with the formation of the generative cell. The paper reports on studies that are attempting to determine the effects acid rain may have on these crucial stages in the life histories of northeastern tree species. The first stage of this work assessed the effects of acidity in the growth medium on in vitro pollen germination for four deciduous forest species common to central New York State, Betula lutea (yellow birch), B. lenta (black birch), Acer saccharum (sugar maple), and Cornus florida (flowering dogwood). Measurements were taken at the end of the growth period to determine the percentage of grains which had germinated, and to estimate the average tube length. To determine the effects of pollen on the growth medium, the pH of the germination drop was measured at the end of the growth period.

  7. GERMINATION OF GRASSES DUE TO INOCULATION DIAZOTROPHIC BACTERIA

    Directory of Open Access Journals (Sweden)

    C. D. A. Moreira

    2014-07-01

    Full Text Available The germination of forage grasses suffers from numbness and a natural tendency to low quality. The use of microorganisms inoculated in seeds with the purpose of increasing and meet the demand of some nutrient has been shown to be efficient, but the role of the microorganism in germination and rate of force is still unknown. Therefore the goal as study was to evaluate the germination rate of seeds of three cultivars of Brachiaria brizantha CV. Marandu, b., b. brizantha CV. Xaraés and b. humidícola cv Tupi and a cultivar of millet, P. hybrid cv Massai depending on the bacterium Azospirillum brasilense diazotrofic inoculation (nitrogen-fixing. Germination test was used in seed dispersal to assess the effect of first count (VPC in the treatments with and without inoculation. It was done also conducted further tests of electrical conductivity, weight of thousand seeds and water content. The delineation used was randomized entirely (DIC and the statistical analysis carried out through the analysis of variance and comparison of means using the Tukey test, the 5% probability. Massai grass seeds have the highest rate of force of first count in both treatments. Inoculation of bacterium Azospirillum brasilense did not affect the values of force of first count on seeds of the cultivars Marandu, Xaraés, Tupi and Massai. The seeds of the massai have higher germination speed relative the other cultivars evaluated when inoculated.

  8. The Determination of Different Germination Applications on Some Sage Species

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    İmge İhsane Özcan

    2014-05-01

    Full Text Available Sage, which belongs to Labiatae family and contains essential oils, is a typical Mediterranean plant. Being an important and one of the biggest species of this family, sage is said to be named being inspired by the word "Salveo" which means “saver” or “healer” in Latin. Salvia genus is represented by about 900 species on earth. There are 97 natural species of this genus in Turkey’s flora. There is dormancy in seeds of Salvia genus and having mucilage-like seed-coats is an inhibiting factor for germination. Seed germination studies of these species are of great importance in determining production strategies. This research is carried out at 25/15°C, 12 hours in light and 12 hours in dark environment to determine the effects of various germination applications (ethylene, gibberellin, PEG 8000, salicylic acid and seaweed and pre-treatments (pre-drying, pre-cooling and untreated in four species (S. fruticosa, S. officinalis, S. pomifera, S. tomentosa. These trials were conducted at the Department of Field Crops Laboratory of Adnan Menderes University according to completely randomized design with three factors with three replications. Important differences were observed about the germination rate and germination power among the species.

  9. Evaluation of Oxygen Deficit Stress on Germination Indicators and Seedling

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    F Hoseini

    2012-06-01

    Full Text Available To investigate the relationship oxygen deficit stress on germination indicators and seedling growth of five wheat cultivars in laboratory condition, an experiment with Randomized Complete Block design in factorial arrangement with three replications was conducted in 2008. The treatments consisted of five wheat cultivars (Chamran, Flat, Roshan, Stare and Shole as A factor, and two oxygen level (normal seed and seed under oxygen deficit stress conditions as B factor in each of these figures was done. Results showed that oxygen deficit stress caused to decrease for various cultivars germination percentage, germination rate, allometric coefficient, seed vigor index and other germination indicators. Therefore, this test as a suitable method for determining the quality of various seed lot can be used in the water logging condition. In addition, among different cultivars characterized that Roshan cultivar was more resistant to oxygen deficit stress than Chamran, Flat and Star cultivars. Although Chamran cultivar is common cultivar in Khouzestan, but of look most germination indicators arranged as weak seed class. The highest correlation coefficients among the tested cultivars have been related to seed vigor with seedling length and dry weight of radicle with seedling with 0.92 and 0.90, respectively.

  10. Temperature Dependent Seed Germination of Dalbergia nigra Allem (Leguminosae

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    Fernanda G. A. Ferraz-Grande

    2001-12-01

    Full Text Available The germination of endangered species Dalbergia nigra was studied and 30.5° C was found as optimum temperature, although the species presented a broad temperature range where germination occurs and light had no effect. The analysis of kinetics of seed germination confirmed the asynchronized germination below and above the optimum temperature. The light insensitive seed and germination also at high temperatures indicated that D. nigra could occur both in understories and gaps where the mean temperature was high.A germinação de sementes de Dalbergia nigra Allem, comumente conhecida como jacarandá-da-Bahia, caviúna, jacarandá, uma espécie em extinção, foi estudada e determinamos a temperatura ótima de 30,5° C. A espécie apresenta uma ampla faixa de temperatura onde a germinação ocorre e a luz branca não influenciou o processo. A análise da cinética da germinação de sementes confirma a germinação não sincronizada acima e abaixo da temperatura ótima de germinação. A semente insensível à luz e a germinação também em altas temperaturas indicam que D. nigra pode ocorrer tanto na sombra da vegetação bem como em clareiras.

  11. Studies concerning the germination of hop seeds (Humulus lupulus L.

    Directory of Open Access Journals (Sweden)

    Tiberiu SUCIU

    1977-08-01

    Full Text Available Dans les conditions normales les semences de houblon germent avec un faible pourcentage a peine 3-5%. Sur le plan mondial, certaines etudes ont ete faites afin de determiner les causes occasionnant cette faible germination. Malgre tout, les resultants obtenus pratiquement ne s'averent pas encourangeants (2, 3, 4. Concernant les semenes entieres, la germination d'une facon speciale interesse l'anveloppe seminale impermeable a l'eau et a l'oxygene. La temperature dans les differents phases de germination joue aussi un role tres important (1, 2, 5,6. Parlant toujours des semences de houblon, on considere que la germination est inhibee par des substances ameres et des resins continues dans le pericarpe enpechant ainsi, la penetration de l'eau et de l'oxygene jusqu'a l'embryon (2, 3. Ayant aborde ce theme dans un sens complexe et a l'egard de tout ce qui precede, l'amelioration de la germination, des semences obtenuus par hybridation, devient une necessite.

  12. The germinal center antibody response in health and disease.

    Science.gov (United States)

    DeFranco, Anthony L

    2016-01-01

    The germinal center response is the delayed but sustained phase of the antibody response that is responsible for producing high-affinity antibodies of the IgG, IgA and/or IgE isotypes. B cells in the germinal center undergo re-iterative cycles of somatic hypermutation of immunoglobulin gene variable regions, clonal expansion, and Darwinian selection for cells expressing higher-affinity antibody variants. Alternatively, selected B cells can terminally differentiate into long-lived plasma cells or into a broad diversity of mutated memory B cells; the former secrete the improved antibodies to fight an infection and to provide continuing protection from re-infection, whereas the latter may jumpstart immune responses to subsequent infections with related but distinct infecting agents. Our understanding of the molecules involved in the germinal center reaction has been informed by studies of human immunodeficiency patients with selective defects in the production of antibodies. Recent studies have begun to reveal how innate immune recognition via Toll-like receptors can enhance the magnitude and selective properties of the germinal center, leading to more effective control of infection by a subset of viruses. Just as early insights into the nature of the germinal center found application in the development of the highly successful conjugate vaccines, more recent insights may find application in the current efforts to develop new generations of vaccines, including vaccines that can induce broadly protective neutralizing antibodies against influenza virus or HIV-1.

  13. Seed dispersal pattern and germination test of Rhodiola sachalinensis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The survey of seed dispersal of Rhodiola sachalinensis was carried out in Changbai Mountain in 1997. It was discovered that the dispersal of seed is not equal in all directions, but concentrates in the East and North to the cluster. Rh. sachalinensis seeds for germination test were collected from Changbai Mountains area (Antu County, Jilin Province) and Dahailin Migrating Conservation Base (Dahailing Forestry Bureau, Heilongjiang Province). The seeds were treated with 2% KNO3 for 10h and 0.02% GA3 for 5h immediately after the collection. The germinating rate ((85.33%) of the seeds from Dahailin was obviously higher than that (72.66%) from Changbai Mountains. After being stored at 0-5 (C for 10 months, the seeds were treated again with the same concentration of hormone mentioned above for germination test. The experimental results showed that there was almost no difference in germinating rate between newly collected seeds and 10-month storage seeds, which indicated that low-temperature storage can extend the life of seeds, and that the germinating rate increases with increasing of hormone concentration.

  14. Dormancy and germination: How does the crop seed decide?

    Science.gov (United States)

    Shu, K; Meng, Y J; Shuai, H W; Liu, W G; Du, J B; Liu, J; Yang, W Y

    2015-11-01

    Whether seeds germinate or maintain dormancy is decided upon through very intricate physiological processes. Correct timing of these processes is most important for the plants life cycle. If moist conditions are encountered, a low dormancy level causes pre-harvest sprouting in various crop species, such as wheat, corn and rice, this decreases crop yield and negatively impacts downstream industrial processing. In contrast, a deep level of seed dormancy prevents normal germination even under favourable conditions, resulting in a low emergence rate during agricultural production. Therefore, an optimal seed dormancy level is valuable for modern mechanised agricultural systems. Over the past several years, numerous studies have demonstrated that diverse endogenous and environmental factors regulate the balance between dormancy and germination, such as light, temperature, water status and bacteria in soil, and phytohormones such as ABA (abscisic acid) and GA (gibberellic acid). In this updated review, we highlight recent advances regarding the molecular mechanisms underlying regulation of seed dormancy and germination processes, including the external environmental and internal hormonal cues, and primarily focusing on the staple crop species. Furthermore, future challenges and research directions for developing a full understanding of crop seed dormancy and germination are also discussed.

  15. The functions of the endosperm during seed germination.

    Science.gov (United States)

    Yan, Dawei; Duermeyer, Lisza; Leoveanu, Catalina; Nambara, Eiji

    2014-09-01

    In angiosperms, a double fertilization event initiates the development of two distinct structures, the embryo and endosperm. The endosperm plays an important role in supporting embryonic growth by supplying nutrients, protecting the embryo and controlling embryo growth by acting as a mechanical barrier during seed development and germination. Its structure and function in the mature dry seed is divergent and specialized among different plant species. A subset of endospermic tissues are composed of living cells even after seed maturation, and play an active role in the regulation of seed germination. Transcriptome analysis has provided new insights into the regulatory functions of the endosperm during seed germination. It is well known that the embryo secretes signals to the endosperm to induce the degradation of the seed reserve and to promote endosperm weakening during germination. Recent advances in seed biology have shown that the endosperm is capable of sensing environmental signals, and can produce and secrete signals to regulate the growth of the embryo. Thus, germination is a systemic response that involves bidirectional interactions between the embryo and endosperm.

  16. Optimal treatment increased the seed germination of Salvia verticillata L.

    Directory of Open Access Journals (Sweden)

    ALALEH KHAKPOOR

    2015-12-01

    Full Text Available Most seeds of the medicinal species are variable regarding their ecological compatibility with environmental conditions. Therefore, identifying the ecophysiological factors that affect dormancy and create optimal conditions for seed germination of medicinal plants is necessary for their culture and production. To evaluate the effect of different treatments on seed germination of medicinal species of Salvia verticillata, collected in the summer of 2010 in Eastern Azarbaijan, we have performed completely randomized experimental tests with 4 replications. The experimental design of treatment prior to growth included: scrape the skin with sandpaper, treatment with 500 ppm gibberellic acid for 24 and 48 h, treatment with citric acid for 10, 20 and 30 minutes, chilling for 2 and 4 weeks, treatment with warm water at 70°C and control treatment. Results showed that the effect of different treatments was significant on seed germination percent of the medicinal plant Salvia verticillata. Scrape the skin with sandpaper, citric acid treatment for 10, 20 and 30 minutes, and gibberellic acid treatment for 24 hours, increased the germination percentage compared to the control treatment. The most positive impact was observed on the dormancy breaking and germination of medicinal species Salvia verticillata.

  17. Involvement of Coat Proteins in Bacillus subtilis Spore Germination in High-Salinity Environments.

    Science.gov (United States)

    Nagler, Katja; Setlow, Peter; Reineke, Kai; Driks, Adam; Moeller, Ralf

    2015-10-01

    The germination of spore-forming bacteria in high-salinity environments is of applied interest for food microbiology and soil ecology. It has previously been shown that high salt concentrations detrimentally affect Bacillus subtilis spore germination, rendering this process slower and less efficient. The mechanistic details of these salt effects, however, remained obscure. Since initiation of nutrient germination first requires germinant passage through the spores' protective integuments, the aim of this study was to elucidate the role of the proteinaceous spore coat in germination in high-salinity environments. Spores lacking major layers of the coat due to chemical decoating or mutation germinated much worse in the presence of NaCl than untreated wild-type spores at comparable salinities. However, the absence of the crust, the absence of some individual nonmorphogenetic proteins, and the absence of either CwlJ or SleB had no or little effect on germination in high-salinity environments. Although the germination of spores lacking GerP (which is assumed to facilitate germinant flow through the coat) was generally less efficient than the germination of wild-type spores, the presence of up to 2.4 M NaCl enhanced the germination of these mutant spores. Interestingly, nutrient-independent germination by high pressure was also inhibited by NaCl. Taken together, these results suggest that (i) the coat has a protective function during germination in high-salinity environments; (ii) germination inhibition by NaCl is probably not exerted at the level of cortex hydrolysis, germinant accessibility, or germinant-receptor binding; and (iii) the most likely germination processes to be inhibited by NaCl are ion, Ca(2+)-dipicolinic acid, and water fluxes.

  18. Common QTL Affect the Rate of Tomato Seed Germination under Different Stress and Nonstress Conditions

    Science.gov (United States)

    Foolad, Majid R.; Subbiah, Prakash; Zhang, Liping

    2007-01-01

    The purpose of this study was to determine whether the rates of tomato seed germination under different stress and nonstress conditions were under common genetic controls by examining quantitative trait loci (QTL) affecting such traits. Seeds of BC1 progeny of a cross between a slow-germinating tomato breeding line and a rapid-germinating tomato wild accession were evaluated for germination under nonstress as well as cold, salt, and drought stress conditions. In each treatment, the most rapidly-germinating seeds were selected, grown to maturity, and subjected to molecular marker analysis. A selective genotyping approach detected between 6 and 9 QTL affecting germination rate under each of the four conditions, with a total of 14 QTL identified. Ten QTL affected germination rate under 2 or 3 conditions, which were considered germination-related common QTL. Four QTL affected germination rate only in one treatment, which were considered germination-related, condition-specific QTL . The results indicated that mostly the same QTL affected seed germination under different stress and nonstress conditions, supporting a previous suggestion that similar physiological mechanisms contribute to rapid seed germination under different conditions. Marker-assisted selection for the common QTL may result in progeny with rapid seed germinability under different conditions. PMID:18317505

  19. Common QTL affect the rate of tomato seed germination under different stress and nonstress conditions.

    Science.gov (United States)

    Foolad, Majid R; Subbiah, Prakash; Zhang, Liping

    2007-01-01

    The purpose of this study was to determine whether the rates of tomato seed germination under different stress and nonstress conditions were under common genetic controls by examining quantitative trait loci (QTL) affecting such traits. Seeds of BC(1) progeny of a cross between a slow-germinating tomato breeding line and a rapid-germinating tomato wild accession were evaluated for germination under nonstress as well as cold, salt, and drought stress conditions. In each treatment, the most rapidly-germinating seeds were selected, grown to maturity, and subjected to molecular marker analysis. A selective genotyping approach detected between 6 and 9 QTL affecting germination rate under each of the four conditions, with a total of 14 QTL identified. Ten QTL affected germination rate under 2 or 3 conditions, which were considered germination-related common QTL. Four QTL affected germination rate only in one treatment, which were considered germination-related, condition-specific QTL . The results indicated that mostly the same QTL affected seed germination under different stress and nonstress conditions, supporting a previous suggestion that similar physiological mechanisms contribute to rapid seed germination under different conditions. Marker-assisted selection for the common QTL may result in progeny with rapid seed germinability under different conditions.

  20. Effects of KNO3 pretreatment and temperature on seed germination of Sorbus pohuashanensis

    Institute of Scientific and Technical Information of China (English)

    BIAN Lei; YANG Ling; WANG Jian-an; SHEN Hai-long

    2013-01-01

    We characterized the effects of KNO3 pretreatment and germination temperature on dormancy breaking and germination of mature mountain ash seeds.Seeds treated with KNO3 and germinated at 25 ℃followed by 5 ℃ had significantly higher germination percentages and germination potentials (51% and 49%,respectively),compared with controls.These treated seeds also exhibited reduced germination initiation times (minimum of 48 days),and elevated germination rate indices (up to 97).The germination of seeds subjected to long-term cold storage (2 years at 0-5 ℃) was also significantly improved by 3 days of 4%KNO3 pretreatment before germinating under a variable temperature regimen (5 ℃ followed by 25 ℃,and followed by 5 ℃).Germination percentages and germination potentials for these cold-stored seeds reached 67% and 54%,respectively,and the germination rate index increased to 126.99.Pretreatment of mountain ash seeds with KNO3 represents a practical,effective,and pollution-free method for improving germination,and can be implemented easily within a variety of nursery settings.

  1. Seed Germination of selected Taxa from Kachchh Desert, India

    Directory of Open Access Journals (Sweden)

    Vinay Madhukar RAOLE

    2010-06-01

    Full Text Available The district of Kachchh contains many culturally important plants. However, their conservation status is little known due to direct and indirect human activities. This study was undertaken with the aim of contributing to the conservation of the native species of these semi-arid regions through germination trials under laboratory conditions. Mature fruits of ten selected species were collected randomly from the known habitats to obtain viable seeds. These seeds were pre-treated with growth regulators singly or in combination after acid scarification or without scarification. Seeds were found to be dormant due to presence of thick seed coat or due to low level of endogenous hormonal level. Most of these seeds required different storage period to mature. Only seeds of Capparis cartilaginea germinated without treatment while the other species required treatments. Addition of growth regulators has enhanced seed germination in few taxa singly and in some plant cases in combination.

  2. Storage polysaccharides in germinating yellow lupine (Lupinus luteus L.

    Directory of Open Access Journals (Sweden)

    Aleksandra Hoffmannowa

    2014-01-01

    Full Text Available The yellow lupine (Lupinus luteus L. cv. Express was cultured for 16 days in light or in darkness. During the first 3 days of germination starch and hemicelluloses were estimated in the seed organs, cotyledons and axis. Later the estimations were performed daily in cotyledons, shoots and roots of the cultured seedlings. Absence of starch was noted in cotyledons of airdry seeds and an abrupt starch synthesis in the first 24 hours of germination. nation. Degradation of starch, and hemicelluloses in cotyledons of the germinating yellow lupine was rapid and correlated strictly with losses in their dry weight. Similarly to starch synthesis, it showed no light dependence. On the other hand, light influenced synthesis of the studied polysaccharides in the shoot and the root of a develaping lupine seedling.

  3. IV. STORAGE AND GERMINATION TESTS ON SHOREA JAVANICA SEEDS

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    M.I.J. UMBOH

    1987-01-01

    Full Text Available Seeds of Shorea javanica K & V (Dipterocarpaceae, were subjected to different treatments of temperature (27 ± 2°C, 20 ± 2°C and < 10°C, coating (ash and paraffin and relative humidity (20, 66 and 86% and their germination capability as well as moisture content assessed after 3, 7, 14 and 30 days of storage. The germination percentage of the seeds stored 30 days in a cloth bag under different conditions of temperature showed highly significant differences (a = 0.01. No significant differences were found on the effect of coating, duration of storage as well as on the interaction between these two factors. The moisture content of the seeds between 13 and 14% gave a germination percentage above 50% after 30 days.

  4. Seed Germination of selected Taxa from Kachchh Desert, India

    Directory of Open Access Journals (Sweden)

    Vinay Madhukar RAOLE

    2010-06-01

    Full Text Available The district of Kachchh contains many culturally important plants. However, their conservation status is little known due to direct and indirect human activities. This study was undertaken with the aim of contributing to the conservation of the native species of these semi-arid regions through germination trials under laboratory conditions. Mature fruits of ten selected species were collected randomly from the known habitats to obtain viable seeds. These seeds were pre-treated with growth regulators singly or in combination after acid scarification or without scarification. Seeds were found to be dormant due to presence of thick seed coat or due to low level of endogenous hormonal level. Most of these seeds required different storage period to mature. Only seeds of Capparis cartilaginea germinated without treatment while the other species required treatments. Addition of growth regulators has enhanced seed germination in few taxa singly and in some plant cases in combination.

  5. Recycling probability and dynamical properties of germinal center reactions

    CERN Document Server

    Meyer-Hermann, M; Or-Guil, M; Meyer-Hermann, Michael; Deutsch, Andreas; Or-Guil, Michal

    2001-01-01

    We introduce a new model for the dynamics of centroblasts and centrocytes in a germinal center. The model reduces the germinal center reaction to the elements considered as essential and embeds proliferation of centroblasts, point mutations of the corresponding antibody types represented in a shape space, differentiation to centrocytes, selection with respect to initial antigens, differentiation of positively selected centrocytes to plasma or memory cells and recycling of centrocytes to centroblasts. We use exclusively parameters with a direct biological interpretation such that, once determined by experimental data, the model gains predictive power. Based on the experiment of Han et al.(1995) we predict that a high rate of recycling of centrocytes to centroblasts is necessary for the germinal center reaction to work reliably. Furthermore, we find a delayed start of the production of plasma and memory cells with respect to the start of point mutations, which turns to be necessary for the optimization process ...

  6. Effect of electron beam irradiation on seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seunghee; Bae, Youngmin [Changwon Univ., Changwon (Korea, Republic of)

    2013-07-01

    Effect of electron beam irradiation on seed germination was investigated in this research. Electron beam of 0.5, 1.0, 1.5 and 2.0 kGy was irradiated to the seeds of lettuce, green onion and cucumber, and the irradiated seeds were incubated at 25 .deg. Cn Nitsch medium solidified with 0.2% Phytagel. Germination percentage and the length of the sprouts were determined after 72 hours. Germination percentage of lettuce seeds was greatly reduced by the irradiation, and that of the green onion and cucumber were moderately reduced or unchanged by the irradiation. Although average length of the lettuce sprouts was reduced severely, that of the green onion and cucumber was unchanged or moderately reduced. Conclusively, electron beam irradiation might be a useful way of disinfecting some plant seeds including green onion and cucumber.

  7. EFFECTS OF LIGHT WAVELENGTHS AND COHERENCE ON BASIDIOSPORES GERMINATION

    Directory of Open Access Journals (Sweden)

    Natalia Poyedinok

    2015-02-01

    Full Text Available The effects of light wavelengths and coherence on basidiospore germination of Agaricus bisporus, Flammulina velutipes, Ganoderma applanatum, Ganoderma lucidum, Hericium erinaceus, Lentinus edodes and Pleurotus ostreatus have been studied. Short-term low-intensity irradiation by coherent (laser light wavelength 488.0 nm and 632.8 nm at doses 45 and 230 mJ/cm2 has significantly increased the number of germinated basidiospores. It has established that there are differences in the photosensitivity not only between species but also between strains. Spores irradiation by 514.5 nm light has been either neutral or inhibitory. A comparative analysis of basidiospores sensitivity to laser and LED light has also been conducted. To stimulate germination of basidiospores and growth of monokaryons the most suitable solution was to use red coherent and incoherent light of 632.8 nm and 660,0 nm for A. bisporus, G. applanatum and P. ostreatus, red and blue coherent light of 632.8 nm and 488,0 nm for F. velutipes, and both red and blue laser and LED light G. lucidum and H. erinaceus and for L. edodes. No essential difference of a continuous wave mode and intermittent mode light effect at the same doses and wavelength on spore germination were revealed. Light influence has reduced germination time and formation of aerial mycelium on agar medium as compared to the original value and increased the growth rate of monosporous isolates. Characterization of basidiospores photosensitivity and development of environmentally friendly stimulating methods of their germination is important for creating highly effective technologies of mushrooms selection and cultivation.

  8. Precocious germination and its regulation in embryos of triticale caryopses

    Directory of Open Access Journals (Sweden)

    Stanisław Weidner

    2014-01-01

    Full Text Available Triticale var. Lasko embryos, isolated from grain gathered at milk ripeness, the beginning of wax ripeness and at full ripeness, were allowed to germinate for 48 h on agar with glucose. The highest incorporation of tritiated adenosine into polyribosomal RNA during germination was found in the ribosome fractions from embryos of grain gathered at full ripeness, lower incorporation was in preparations from embryos of milk ripe grain and the lowest in preparations from embryos of wax ripe grain. Different tendencies were observed in respect to the synthesis of ribosomal proteins. The highest incorporation of 14C-amino acids into ribosomal proteins was found in preparations of ribosome fractions from embryos of milk ripe grain, lower in preparations of embryos from fully ripe grain, the lowest in preparations of embryos from wax ripe grain. ABA (10-4 M completely inhibited the external symptoms of germination of immature embryos, while its inhibition of the synthesis of polyribosomal RNA and ribosomal proteins was greater the more mature the embryos that were germinated. The greatest stimulation of precocious germination by exogenous BA and GA3 was demonstrated in the least mature embryos isolated from milk ripe grain. Under the influence of both stimulators, an increase of the proportion of polyribosomes in the total ribosome fraction occurred in this sample, as did a rise in the intensity of ribosomal protein synthesis. The incorporation of 3H-adenosine into polyribosomal RNA, however, was lower than in the control sample. The results obtained suggest that the regulation of precocious germination of triticale embryos by phyto-hormones is not directly related to transcription.

  9. SEED GERMINATION BEHAVIOUR OF THREE ALPINE SPECIES FROM ULUDAĞ MOUNT,TURKEY

    Directory of Open Access Journals (Sweden)

    HülyaARSLAN

    2013-02-01

    Full Text Available In this study, the germination requirements of three species from alpine belt of Uludağ Mount; Gypsophila olympica Boiss., Matthiola montana Boiss. and Silene rhynchocarpa Boiss. We tested thegermination under (20 °C dark, (20 °C continuous light, and photoperiod 20/10 °C (12/12h with distilled water. Different germination behaviour was found for these three species from closely related habitat conditions. G. olympica showed similar germination percentages in dark, light and photoperiod, and germinated faster in light (3.9 days. S. rhyncocarpa germinated 100 % at all the threeconditions but faster in dark with 2.0 days. M. montana seeds were found to require light for germination. The germination was 27.2 % at dark, whereas the seeds were germinated 90 % under photoperiod.The results can be useful for both in situ and ex situ conservation of these plant species.

  10. Transcriptional dynamics of two seed compartments with opposing roles in Arabidopsis seed germination

    NARCIS (Netherlands)

    Dekkers, S.J.W.; Pearce, S.; Bolderen-Veldkamp, R.P.; Marshall, A.; Widera, P.; Gilbert, J.; Drost, H.G.; Bassel, G.; Muller, K.; King, J.R.; Wood, A.; Grosse, I.; Bentsink, L.

    2013-01-01

    Seed germination is a critical stage in the plant life cycle and the first step toward successful plant establishment. Therefore, understanding germination is of important ecological and agronomical relevance. Previous research revealed that different seed compartments (testa, endosperm, and embryo)

  11. Association mapping of germinability and seedling vigor in sorghum under controlled low-temperature conditions

    National Research Council Canada - National Science Library

    Burrell, A. Millie; Upadhyaya, Hari D; Klein, Robert R; Wang, Yi-Hong; Prasad, P.V. Vara; Klein, Patricia E; Sastry, Dintyala V.S.S.R; Morris, Geoffrey P; Dwivedi, Sangam L

    2016-01-01

    ..., sorghum’s sensitivity to low soil temperatures adversely impacts seed germination. In this study, we evaluated the 242 accessions of the ICRISAT sorghum mini core collection for seed germination and seedling vigor at 12...

  12. Germination of guatambu seeds subjected to two light regimes

    Directory of Open Access Journals (Sweden)

    Karina Guollo

    2015-09-01

    Full Text Available Guatambu (Aspidosperma parvifolium A. DC. is a species that faces extinction in different regions of Brazil. The aim of this study was to evaluate the influence of photoperiod on germination of guatambu seeds at 25°C. The statistical procedure used was factorial design with two factors. Factor A was seed lots (Mother tree A, B, and C and factor B was photoperiod (dark and 12 h of photoperiod. Guatambu seeds are not affected by photoperiod condition during the germination process.

  13. The influence of light on the germination of potato seeds

    Directory of Open Access Journals (Sweden)

    A. Listowski

    2015-06-01

    Full Text Available The influence of white and coloured Light and of the darkness on the germination of potato seeds was investigated. Potato seeds germinate in light as well as in darkness. Bed light is stimulative. Far-red and blue light depending of the origin of the seeds populations acted or inhibitive or only as a delaying factor. The after effect of R after FR or FR after R was also studied. The R-FR or FR-R photoreaction observed by potato seeds, differ from the classic pattern established by lettuce and tomato seeds.

  14. Biorregulator on cotton seed germination and initial growth

    OpenAIRE

    Eduardo Pradi Vendruscolo; Heloisa Bueno de Souza; Lucas Alves de Arruda; Sebastião Ferreira de Lima; Rita de Cássia Félix Alvarez

    2015-01-01

    The objective was to evaluate the effect of a bioregulator applied to seeds, on seed germination, emergence and vigor of cotton seedlings. The treatments were a combination of seeds of two cotton cultivars (FMT 701 and FMT 705) exposed to six doses of plant growth regulator: 0.0; 5.0; 10.0; 15.0; 20.0 and 25.0 ml applied 0.5 kg of seed. The experiment was conducted in a completely randomized design in factorial scheme consists of a 2 x 6, with four replications. Germination, initial growth, e...

  15. Adult neurogenesis without germinal layers: the "atypical" cerebellum of rabbits.

    Science.gov (United States)

    Ponti, G; Crociara, P; Armentano, M; Bonfanti, L

    2010-06-01

    Unlike non mammalian vertebrates, adult neurogenesis in mammals is detectable in highly restricted brain sites. Persistent neurogenesis is thought to depend on stem cells residing in neural stem cell niches which are remnants of the embryonic germinal layers. Local progenitors which retain some proliferative capacity have been identified in the mature brain parenchyma, yet they do not support a constitutive, 'actual' neurogenesis, but rather a 'potential' neurogenesis which does not extrinsecate fully and spontaneously in vivo. In contrast with such a view, genesis of neuronal and glial cells from local progenitors does occur in the peripuberal and adult rabbit cerebellum. This process is independent from persisting germinal layers and involves different cell populations.

  16. Characteristics of spore germination and protonemal development in Hypnum pacleseens

    Institute of Scientific and Technical Information of China (English)

    HUANG Shiliang; LI Min; ZHAO Jiancheng; ZHANG Yuanming; WANG Zhenjie

    2006-01-01

    The spore germination,protonemal development,and gametophyte differentiation of Hypnum pacleseens were observed in cultivation.Photomicrographs showed that spore germination of Hypnum pacleseens occured within the exospore.Its protonema is massive with filamentous chloronema formed inside.The terminal part of the chloronema differentiated into filamentous caulonema and its rhizoid was derived from the apical cell of the filamentous chloronema.The initial cell of gametophyte differentiated from chloronema and caulonema.Sporeling type of Hypnum pacleseens is developmentally similar to Glyphmitrium-type.

  17. Quantitative trait loci analysis for rice seed vigor during the germination stage*

    OpenAIRE

    Wang, Zhou-fei; Wang,Jian-fei; Bao, Yong-Mei; Wang, Fu-Hua; Zhang, Hong-sheng

    2010-01-01

    Seed vigor is an important characteristic of seed quality, and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment. In the present study, the quantitative trait loci (QTLs) of three traits for rice seed vigor during the germination stage, including germination rate, final germination percentage, and germination index, were investigated using one recombinant inbred line (RIL) population derived from a cross between japonica Dagua...

  18. Common QTL Affect the Rate of Tomato Seed Germination under Different Stress and Nonstress Conditions

    OpenAIRE

    Foolad, Majid R.; Subbiah, Prakash; Zhang, Liping

    2007-01-01

    The purpose of this study was to determine whether the rates of tomato seed germination under different stress and nonstress conditions were under common genetic controls by examining quantitative trait loci (QTL) affecting such traits. Seeds of BC1 progeny of a cross between a slow-germinating tomato breeding line and a rapid-germinating tomato wild accession were evaluated for germination under nonstress as well as cold, salt, and drought stress conditions. In each treatment, the most rapid...

  19. QTL Mapping of Low-Temperature Germination Ability in the Maize IBM Syn4 RIL Population

    OpenAIRE

    Shuaidong Hu; Thomas Lübberstedt; Guangwu Zhao; Michael Lee

    2016-01-01

    Low temperature is the primary factor to affect maize sowing in early spring. It is, therefore, vital for maize breeding programs to improve tolerance to low temperatures at seed germination stage. However, little is known about maize QTL involved in low-temperature germination ability. 243 lines of the intermated B73×Mo17 (IBM) Syn4 recombinant inbred line (RIL) population was used for QTL analysis of low-temperature germination ability. There were significant differences in germination-rela...

  20. Artificial seed germination and seedling production ofZostera marina L. by salinity manipulation

    Institute of Scientific and Technical Information of China (English)

    LIU Yunlong; ZHANG Xuelei; SONG Wei; WANG Zongling

    2016-01-01

    Vast declines inZostera marina seagrass beds demand effective methods of rehabilitation. In this study, we developed a practical method by reducing salinity to induce seed germination followed with recovering salinity to facilitate seedling production ofZ. marina. The results showed thatZ. marina seeds collected from natural seawater (salinity 30) were induced to germinate at reduced salinities. Percent germination (GR) was higher and mean-time-to-germinate (MTG) was shorter at lower salinities. The highestGR and shortestMTG occurred at salinity 0 (deionized freshwater). After germination in freshwater, seeds could develop into seedlings at salinities 5–30 and continue the growth. Viability or development of germinated seeds was not significantly different during the 40 d of post-germination incubation at salinities 5–15 after 1–20 d of germination in freshwater. However, during the process of translating germinated seeds from salinity 0 and 5 to salinity 30, reducing the gradients of post-germination acclimation facilitated more seeds forming seedlings in less time. On average, after 60 d of static incubation, including 20 d in freshwater for germination followed with immediate shift to salinity 5 and increasing to salinity 30 at increment of 5 every two days until cultivation at constant salinity 30, 33% ofZ. marina seeds produced healthy seedlings. The results indicate that the salinity-manipulation based method of artificial germination and seedling production is practical and effective in supporting rehabilitation ofZ. marina bed.

  1. Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes.

    Science.gov (United States)

    Lone, A B; Colombo, R C; Andrade, B L G; Takahashi, L S A; Faria, R T

    2016-06-01

    The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

  2. Physical characterization of Rhipsalis (Cactaceae fruits and seeds germination in different temperatures and light regimes

    Directory of Open Access Journals (Sweden)

    A. B. Lone

    Full Text Available Abstract The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

  3. Isolation and characterization of the gene encoding the starch debranching enzyme limit dextrinase from germinating barley

    DEFF Research Database (Denmark)

    Kristensen, Michael; Lok, Finn; Planchot, Véronique

    1999-01-01

    expression is high during germination and the steady state transcription level reaches a maximum at day 5 of germination. The deduced amino acid sequence corresponds to the protein sequence of limit dextrinase purified from germinating malt, as determined by automated N-terminal sequencing of tryptic...

  4. The role of water channel proteins and nitric oxide signaling in rice seed germination

    Institute of Scientific and Technical Information of China (English)

    Hong-Yan Liu; Xin Yu; Da-Yong Cui; Mei-Hao Sun; Wei-Ning Sun; Zhang-Cheng Tang; Sang-Soo Kwak; Wei-Ai Su

    2007-01-01

    Previous studies have demonstrated the possible role of several aquaporins in seed germination. But systematic investigation of the role of aquaporin family members in this process is lacking. Here, the developmental regulation of plasma membrane intrinsic protein (PIP) expression throughout germination and post-germination processes in rice embryos was analyzed. The expression patterns of the PIPs suggest these aquaporins play different roles in seed germination and seedling growth. Partial silencing of the water channel genes, OsPIP1; 1 and OsPIP1;3, reduced seed germination while over-expression of OsPIPl;3 promoted seed germination under water-stress conditions. Moreover, spatial expression analysis indicates that OsPIP1;3 is expressed predominantly in embryo during seed germination. Our data also revealed that the nitric oxide (NO) donors, sodium nitroprusside (SNP) and S-nitrosoglutathione (GSNO), promoted seed germination; furthermore, the NO scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, inhibited germination and reduced the stimulative effects of SNP and GSNO on rice germination. Exogenous NO stimulated the transcription of OsPIP1;1, OsPIP1;2, OsPIP1;3 and OsPIP2;8 in germinating seeds. These results suggest that water channels play an important role in seed germination, acting, at least partly, in response to the NO signaling pathway.

  5. Phytochrome and Seed Germination. III. Action of Prolonged Far Red Irradiation on the Germination of Tomato and Cucumber Seeds.

    Science.gov (United States)

    Yaniv, Z; Mancinelli, A L; Smith, P

    1967-11-01

    Prolonged irradiation with continuous or intermittent far red prevents the germination of tomato and cucumber seeds. The inhibitory efficiency of intermittent far red decreases with the lengthening of the interval between successive irradiations, and with the increase of temperature. If each far red irradiation is followed by red, germination is restored. Intermittent far red is less inhibitory than intermittent red-far red when red is given immediately before each far red. This effect is more evident when the interval between successive irradiation becomes longer.

  6. Classification of temperature response in germination of Brassicas

    Science.gov (United States)

    Since soil temperature affects germination and emergence of canola (Brassica napus L.), mustard [B. juncea (L.) Czerniak. and Sinapsis alba L.], and camelina [Camelina sativa (L.) Crantz.], planting dates have to be adjusted to prevent crop failures. These crops can be used as biofuel feedstocks, a...

  7. PICKLE acts during germination to repress expression of embryonic traits

    Science.gov (United States)

    Li, Hui-Chun; Chuang, King; Henderson, James T.; Rider, Stanley Dean; Bai, Yinglin; Zhang, Heng; Fountain, Matthew; Gerber, Jacob; Ogas, Joe

    2008-01-01

    SUMMARY PICKLE (PKL) codes for a CHD3 chromatin remodeling factor that plays multiple roles in Arabidopsis growth and development. Previous analysis of the expression of genes that exhibit PKL-dependent regulation suggested that PKL acts during germination to repress expression of embryonic traits. In this study, we examined the expression of PKL protein to investigate when and where PKL acts to regulate development. A PKL:eGFP translational fusion is preferentially localized in the nucleus of cells, consistent with the proposed role for PKL as a chromatin remodeling factor. A steroid-inducible version of PKL - a fusion of PKL to the glucocorticoid receptor (PKL:GR) - was used to examine when PKL acts to repress expression of embryonic traits. We found that activation of PKL:GR during germination was sufficient to repress expression of embryonic traits in the primary roots of pkl seedlings whereas activation of PKL:GR after germination had little effect. In contrast, we observed that PKL is required continuously after germination to repress expression of PHERES1, a type I MADS box gene that is normally expressed during early embryogenesis in wild-type plants. Thus PKL acts at multiple points during development to regulate patterns of gene expression in Arabidopsis. PMID:16359393

  8. Live-imaging of Bacillus subtilis spore germination and outgrowth

    NARCIS (Netherlands)

    Pandey, R.

    2014-01-01

    Spores of Gram-positive bacteria such as Bacillus and Clostridium cause huge economic losses to the food industry. In food products, spores survive under food preservation conditions and subsequent germination and outgrowth eventually causes food spoilage. Therefore efforts are being made to elimina

  9. Mechanism and control of Genipa americana seed germination

    NARCIS (Netherlands)

    Queiroz, S.E.E.; Silva, da E.A.A.; Davide, A.C.; Jose, A.C.; Silva, A.T.; Fraiz, A.C.R.; Faria, J.M.R.; Hilhorst, H.W.M.

    2012-01-01

    Genipa americana (Rubiaceae) is important for restoration of riparian forest in the Brazilian Cerrado. The objective was to characterize the mechanism and control of germination of G. americana to support uniform seedling production. Morphology and morphometrics of seeds, embryo and endosperm were a

  10. Asymbiotic seed germination and in vitro propagation of ...

    African Journals Online (AJOL)

    Joe Krawczyszyn

    2015-10-13

    Oct 13, 2015 ... seeds, regardless of storage time and storage temperature. Whole leaf and ... subjected to drying (to 5% moisture content) and freezing. (-20°C) ... distilled water. ... 0.1 N NaOH or HCl before the addition of agar. .... There is an increase in germination rate for seeds .... Skoog medium at half-strength of salts.

  11. Influence of gamma irradiation on pollen viability, germination ability ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... cannot fertilize the egg-cell and the polar nuclei. These .... irradiated pollens by sitting drop culture method (Zaman, 2006). The medium was ... and 24 h for germination ability tests of setting the experiment. (Şensoy et al.

  12. Biosynthesis of germination stimulants of parasitic weeds Striga and Orobanche

    NARCIS (Netherlands)

    Sun, Z.

    2008-01-01

    My research focused on the biosynthetic origin of germination stimulants of the root parasitic plants, Striga spp. and Orobanche spp., which have an increasing impact on cereal and other economically important crops in many regions of the world. The traditional control methods are not sufficient and

  13. Stochastic discrete event simulation of germinal center reactions

    NARCIS (Netherlands)

    Figge, MT

    2005-01-01

    We introduce a generic reaction-diffusion model for germinal center reactions and perform numerical simulations within a stochastic discrete event approach. In contrast to the frequently used deterministic continuum approach, each single reaction event is monitored in space and time in order to simu

  14. Fast neutron sensitivity of dry and germinating tomato seeds

    NARCIS (Netherlands)

    Contant, R.B.

    1970-01-01

    A study was made of changes in fast neutron effectiveness during the hydration and germination of tomato seeds. The main findings and conclusions are the following,

    Section 3.6

    Samples of unirradiated seeds and their constituent parts (seedcoat+endosperm and embryo) were taken at short

  15. Bacillus subtilis Spores Germinate in the Chicken Gastrointestinal Tract▿

    OpenAIRE

    Stephen T Cartman; La Ragione, Roberto M.; Woodward, Martin J.

    2008-01-01

    A number of poultry probiotics contain bacterial spores. In this study, orally administered spores of Bacillus subtilis germinated in the gastrointestinal (GI) tracts of chicks. Furthermore, 20 h after spores were administered, vegetative cells outnumbered spores throughout the GI tract. This demonstrates that spore-based probiotics may function in this host through metabolically active mechanisms.

  16. Biorregulator on cotton seed germination and initial growth

    Directory of Open Access Journals (Sweden)

    Eduardo Pradi Vendruscolo

    2015-12-01

    Full Text Available The objective was to evaluate the effect of a bioregulator applied to seeds, on seed germination, emergence and vigor of cotton seedlings. The treatments were a combination of seeds of two cotton cultivars (FMT 701 and FMT 705 exposed to six doses of plant growth regulator: 0.0; 5.0; 10.0; 15.0; 20.0 and 25.0 ml applied 0.5 kg of seed. The experiment was conducted in a completely randomized design in factorial scheme consists of a 2 x 6, with four replications. Germination, initial growth, emergency speed index and seedling emergence were evaluated. Cotton cultivars FMT 701 and FMT 705 differently respond to application of plant growth regulator on seed. The application of plant growth regulator to FMT 701 cultivar cotton seeds did not affect germination, resulted in less vigorous seedlings and reduction in its emergence. For FMT 705 cultivar, the dose of 25 mL produced more vigorous seedlings, reduced seedling emergence, but did not affect seed germination.

  17. Proteomic analysis of Arabidopsis seed germination and priming

    NARCIS (Netherlands)

    Gallardo, K.; Job, C.; Groot, S.P.C.; Puype, M.; Demol, H.; Vandekerckhove, J.; Job, D.

    2001-01-01

    To better understand seed germination, a complex developmental process, we developed a proteome analysis of the model plant Arabidopsis for which complete genome sequence is now available. Among about 1,300 total seed proteins resolved in two-dimensional gels, changes in the abundance (up- and down-

  18. Conditions and Stimulation for Germination in Glycyrrhiza uralensis Fisch Seeds

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Evaluation of seed quality is the key to seed distributing and seeding of Glycyrrhiza uralensis Fisch, as an important species for pharmacy and soil conservation. Here, we study the effects of light and temperature on seed germination and mechanical and chemical scarification on breaking the seed coat. Seeds were collected in 2004, 2005, and 2006, placed in Petri dishes, and incubated at constant temperature 20, 25, and 30℃, and alternating temperature 15-25, 20-30, 15-30, and 20-35℃ under either an 8 h photoperiod or total darkness for 28 consecutive days. Different methods were used to break the dormancy owing to hard seededness in this species such as chemical scarification by immersing in concentrated sulphuric acid for 5, 10, 15, 20, 25, 30, 45, and 60 min, in 0.2% KNO3 solution to saturate the seedbed, and prechilling for 7 d at 7℃ and mechanical scarification by cutting. The results showed that alternating temperature at 20-30℃ with 8 h photoperiod and 16 h darkness was optimum for G. Uralensis seed germinating in the laboratory. Hard seeds were broken by concentrated sulphuric acid soaking or mechanical scarification by cutting. Germination of seeds harvested in two different years was both promoted by immersing for 30-45 min in concentrated sulphuric acid. KNO3 solution was ineffective for reducing hard seeds. During seed germinating, the first count was on the 7th day and the last count was on the 14th day.

  19. Environmental factors for germination of Sclerotinia sclerotiorum sclerotia

    Science.gov (United States)

    Basal stalk rot of sunflower is an economically important and rather unique disease among crops that are susceptible to Sclerotinia sclerotiorum. This disease is the result of myceliogenic germination of sclerotia whereby the vegetative hyphae infect the sunflower below the soil level. In contrast, ...

  20. Sugar signalling during germination and early seedling establishment in Arabidopsis

    NARCIS (Netherlands)

    Dekkers, S.J.W.

    2006-01-01

    Sugars have pronounced effects on many plant processes like gene expression, germination and early seedling development. Several screens for sugar insensitive mutants were performed to identify genes involved in sugar response pathways using the model plant Arabidopsis. These include sun, gin and si

  1. Effects of water stress and seed mass on germination and ...

    African Journals Online (AJOL)

    enoh

    2012-03-01

    Mar 1, 2012 ... important restriction factors to seed germination because of the delay in its initiation or ... has little rain, resulting in water as a limiting factor to plant growth. ..... The influence of seed size, shape and treatment on inbred seed ...

  2. Characterization of germination receptors of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Hornstra, L.M.; Vries, de Y.P.; Wells-Bennik, M.H.J.; Vos, de W.M.; Abee, T.

    2006-01-01

    Specific amino acids, purine ribonucleosides, or a combination of the two is required for efficient germination of endospores of Bacillus cereus ATCC 14579. A survey including 20 different amino acids showed that L-alanine, L-cysteine, L-threonine, and L-glutamine are capable of initiating the germi

  3. A simple staining method for observation of germinated Striga seeds

    NARCIS (Netherlands)

    Shusheng Long,; Lendzemo, V.W.; Kuyper, T.W.; Zhengsheng Kang,; Vierheilig, H.; Steinkellner, S.

    2008-01-01

    In vitro techniques are essential for Striga research and the development of appropriate control methods. In the laboratory, pre-screening of non-host or false-host plants of Striga for trap cropping or the screening of hosts for resistance involves visual evaluation of Striga seed germination that

  4. Spatial model of affinity maturation in germinal centers

    NARCIS (Netherlands)

    Kesmir, C.; Boer, R.J. de

    2003-01-01

    Affinity maturation of humoral responses to T-cell-dependent antigens occurs in germinal centers (GC). In GCs antigen-specific B cells undergo rounds of somatic mutations that alter their affinity. High-affinity mutants take over GCs very soon after they appear; the replacement rate is as high as 4

  5. Germination strategy of the East African savanna tree Acacia tortilis

    NARCIS (Netherlands)

    Loth, P.E.; Boer, de W.F.; Heitkönig, I.M.A.; Prins, H.H.T.

    2005-01-01

    Germination of Acacia tortilis seeds strongly depends on micro-site conditions. In Lake Manyara National Park, Tanzania, Acacia tortilis occurs abundantly in recently abandoned arable fields and in elephant-mediated gaps in acacia woodland, but does not regenerate in grass swards or beneath

  6. Inhibitory effects of monoterpenes on seed germination and seedling growth.

    Science.gov (United States)

    Kordali, Saban; Cakir, Ahmet; Sutay, Sunay

    2007-01-01

    Monoterpenes, the chemical constituents of essential oils found in plants, are known biologically active compounds. The present study was conducted to investigate the inhibitory effects of 30 monoterpenes including monoterpene hydrocarbons and oxygenated monoterpenes on seed germination and seedling growth of Amaranthus retroflexus, Chenopodium album and Rumex crispus under laboratory conditions. The monoterpenes were applied at contents of 10 and 20 microl for liquid compounds and 10 and 20 microg for solid compounds. The results show that most of the monoterpenes significantly inhibited seed germination and seedling growth of the tested plants. Oxygenated monoterpenes including beta-citronellol, nerol and terpinen-4-ol completely inhibited seed germination and seedling growth of all tested plants. Their inhibitory effects were also stronger than that of the herbicide 2,4-D. In general, monoterpenes were less effective against seed germination and seedling growth of C. album as compared with R. crispus and A. retroflexus. Phytotoxic effects of monoterpene hydrocarbons were found to be lower than those of oxygenated monoterpenes. The alcohol derivatives of oxygenated monoterpenes were also found to be more phytotoxic as compared with their acetate derivatives. Based on the present results, it can be concluded that the oxygenated monoterpenes can be used as potential bio-herbicides.

  7. The maturation and germination of Phytophthora ramorum Chlamydospores

    Science.gov (United States)

    Aaron L. Smith; Everett M. Hansen

    2008-01-01

    Chlamydospores are a distinctive feature of Phytophthora ramorum. They are formed quickly in agar, and within colonized leaves. We followed their development and maturation in vitro and in vivo, and studied conditions affecting their germination. Cell walls of mature P. ramorum chlamydospores...

  8. Chaparral & Fire Ecology: Role of Fire in Seed Germination.

    Science.gov (United States)

    Steele, Nancy L. C.; Keeley, Jon E.

    1991-01-01

    An activity that incorporates the concepts of plant structure and function and ecology is described. Students investigate the reasons why some California chaparral seeds germinate only after a fire has burned the surrounding chaparral. The procedure, discussion and analysis questions, expected results, potential problems, and additional activities…

  9. Aspects of the barley seed proteome during development and germination

    DEFF Research Database (Denmark)

    Finnie, Christine; Maeda, K.; Østergaard, O.;

    2004-01-01

    Analysis of the water-soluble barley seed proteome has led to the identification of proteins by MS in the major spots on two-dimensional gels covering the pi ranges 4-7 and 6-11. This provides the basis for in-depth studies of proteome changes during seed development and germination, tissue...

  10. Chaparral & Fire Ecology: Role of Fire in Seed Germination.

    Science.gov (United States)

    Steele, Nancy L. C.; Keeley, Jon E.

    1991-01-01

    An activity that incorporates the concepts of plant structure and function and ecology is described. Students investigate the reasons why some California chaparral seeds germinate only after a fire has burned the surrounding chaparral. The procedure, discussion and analysis questions, expected results, potential problems, and additional activities…

  11. Biosynthesis of germination stimulants of parasitic weeds Striga and Orobanche

    NARCIS (Netherlands)

    Sun, Z.

    2008-01-01

    My research focused on the biosynthetic origin of germination stimulants of the root parasitic plants, Striga spp. and Orobanche spp., which have an increasing impact on cereal and other economically important crops in many regions of the world. The traditional control methods are not sufficient and

  12. Response of soybean seed germination to cadmium and acid rain.

    Science.gov (United States)

    Liu, Ting Ting; Wu, Peng; Wang, Li Hong; Zhou, Qing

    2011-12-01

    Cadmium (Cd) pollution and acid rain are the main environmental issues, and they often occur in the same agricultural region. Nevertheless, up to now, little information on the combined pollution of Cd(2+) and acid rain action on crops were presented. Here, we investigated the combined effect of Cd(2+) and acid rain on the seed germination of soybean. The results indicated that the single treatment with the low level of Cd(2+) (0.18, 1.0, 3.0 mg L(-1)) or acid rain (pH ≥3.0) could not affect the seed germination of soybean, which was resulted in the increased activities of peroxidase and catalase. The single treatment with the high concentration of Cd(2+) (>6 mg L(-1)) or acid rain at pH 2.5 decreased the activities of peroxidase and catalase, damaged the cell membrane and then decreased the seed germination of soybean. Meanwhile, the same toxic effect was observed in the combined treatment with Cd(2+) and acid rain, and the combined treatment had more toxic effect than the single treatment with Cd(2+) or acid rain. Thus, the combined pollution of Cd(2+) and acid rain had more potential threat to the seed germination of soybean than the single pollution of Cd(2+) or acid rain.

  13. Homeopathically prepared gibberellic acid and barley seed germination.

    Science.gov (United States)

    Hamman, B; Koning, G; Lok, K Him

    2003-07-01

    The potentisation process by which homeopathic preparations are produced raises the concern that these medicines have placebo effects only, since they theoretically no longer contain active molecules of the diluted substance. Plant models offer a method of examining the efficacy of homeopathically prepared solutions. This study examined the effects of homeopathically prepared gibberellic acid (HGA3) on the germination performance of barley (Hordeum vulgare L.) seeds. The effect of HGA3 (4-200 cH) on seed germination rate and seedling development was compared to that of the most commonly used form of gibberellic acid (GA3), 0.5 g l(-1), and control (distilled water). The extent and type of response was dependent on the vigour level of the seedlot. Treating seeds from three vigour groups in HGA3 consistently resulted in larger seedlings. High-vigour seeds treated with HGA3 4, 30 and 200 cH germinated faster, and roots of medium-vigour seedlots treated in HGA3 15 cH were longer. Biphasic effects of HGA3 were also demonstrated. As a plant model, germinating barley seeds successfully demonstrated the ability of HGA3 to produce a biological response.

  14. Seed germination in Miconia theaezans (Bonpl. Cogniaux (Melastomataceae

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    Simone Godoi

    2007-07-01

    Full Text Available The effects of light and temperature were studied on the seeds of Miconia theazeans by isothermic and alternating temperature incubations. The optimum temperature for seed germination was determined by final percentage and germination rates as located in the range of 27.5 to 30 °C and by germination kinetics at the range of 19.5 to 30 °C. The germination was dependent on diffusion processes. The minimum and maximum temperatures were 12.5-15°C and 32.5-35°C, respectively. The seeds showed strong light dependence for germination with the necessity of daily 4-6 h white light irradiation for the maximum induction of germination. However, under 30-20 °C alternating temperatures, daily 2 hours white light was enough to induce germination and attained maximum under 4 h photoperiod. The results indicated that M. theazeans presented characteristics of early successional species.O efeito da luz e da temperatura na germinação de sementes de Miconia theazeans foi analisado através de incubações isotérmicas e de alternâncias de temperaturas. Através das porcentagens finais e velocidade de germinação concluímos que a temperatura ótima de germinação localizaram-se entre 27,5 e 30 °C e pela cinética de germinação verificamos que entre 19,5 e 30 °C a germinação é dependente de processos de difusão. As temperaturas mínima e máxima foram de 12,5-15 °C e 32,5-35 °C, respectivamente. As sementes apresentaram forte dependência da presença de luz branca para a indução da germinação com a necessidade de 4-6 horas de luz diária para a máxima indução do processo. Entretanto, com a alternância de temperaturas de 30 e 20 °C, fotoperíodo de 2 horas foi suficiente para a indução da germinação sendo o máximo de indução obtida a partir de 4 horas diárias. Estes resultados indicam que Miconia theazeans é uma espécie importante que coloniza clareiras e áreas perturbadas em uma floresta natural.

  15. Variability in germination and germination dynamics of differently treated seeds of Serbian spruce (Picea omorika Pančić/Purkynĕ

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    Cvjetković Branislav

    2013-01-01

    Full Text Available Genetic-physiological approach was used in the study of the quality of Serbian spruce seed (Picea omorika /Pančić/Purkynĕ, collected in the populations on the left bank of the river Drina. The seed originated from the three populations that represent the overall ecological and productive conditions of Serbian spruce populations in Bosnia and Herzegovina. Two natural populations were selected: Veliki Stolac and Gostilj, and one planted forest population in Srebrenica. The cones were collected in late autumn 2009 and early spring 2010. They were collected from five trees from Srebrenica and Gostilj, and seven trees from Veliki Stolac. Immediately after they were collected, the cones and seeds were processed and germination tests were done. Germination, germination viability and germination dynamics were studied in three categories of seed treatment: 1 control unit (just processed seed, 2 seed stored for six months at 0-4 ºC, 3 seed stored for seven months at 0-4º C and treated with fungicide after five months of storing. The number of germinated seed was observed and noted on the third, fourth, fifth, seventh, tenth, fourteenth, twenty-first and twenty-eighth day. There were significant differences in germination dynamics at the population level and the level of treatment during the first couple of days of germination test. Fungicide (captan acted as an inhibitor on seed germination process. The seeds originating from the largest population of Veliki Stolac showed the best response to storing treatment with fungicide related to germination dynamics. The seed originating from Srebrenica andkept at low temperatures 0-4 °C without treatment with fungicides showed the best result in germination. Regardless of the presence of differences in the dynamics of germination, significant differences in germination regarding different treatments on the last day of the test, were not recorded.

  16. Germination of white radish, buckwheat and qing-geng-cai under low pressure in closed environment.

    Science.gov (United States)

    Hinokuchi, Tsutomu; Oshima, Satoshi; Hashimoto, Hirofumi

    2004-11-01

    In order to cultivate plants under low pressure in closed environment, the germination rate of seeds of white radish was investigated under low pressure, low oxygen partial pressure and condition of pure oxygen. The result of these experiments showed that the germination rate was affected by the oxygen partial pressure. From this fact, it is possible to lower the total pressure by using only the pure oxygen in germination. Furthermore, the germination rates of seeds of buckwheat and qing-geng-cai were also investigated in pure oxygen for the comparison. Consequently, though tendency in germination rate of white radish was similar to qing-geng-cai, it was different from buckwheat.

  17. Cellular recycling of proteins in seed dormancy alleviation and germination

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    Krystyna Oracz

    2016-07-01

    Full Text Available Each step of the seed-to-seed cycle of plant development including seed germination is characterized by a specific set of proteins. The continual renewal and/or replacement of these biomolecules are crucial for optimal plant adaptation. As proteins are the main effectors inside the cells, their levels need to be tightly regulated. This is partially achieved by specific proteolytic pathways via multicatalytic protease complexes defined as 20S and 26S proteasomes. In plants, the 20S proteasome is responsible for degradation of carbonylated proteins, while the 26S being a part of ubiquitin-proteasome pathway (UPP is known to be involved in proteolysis of phytohormone signaling regulators. On the other hand, the role of translational control of plant development is also well documented, especially in the context of pollen tube growth and light signaling. Despite the current progress that has been made in seed biology, the sequence of cellular events that determine if the seed can germinate or not are still far from complete understanding. The role and mechanisms of regulation of proteome composition during processes occurring in the plant’s photosynthetic tissues have been well characterized since many years, but in nonphotosynthetic seeds it has emerged as a tempting research task only since the last decade. This review discusses the recent discoveries providing insights into the role of protein turnover in seed dormancy alleviation, and germination, with a focus on the control of translation and proteasomal proteolysis. The presented novel data of translatome profiling in seeds highlighted that post-transcriptional regulation of germination results from a timely regulated initiation of translation. In addition, the importance of 26S proteasome in the degradation of regulatory elements of cellular signaling and that of the 20S complex in proteolysis of specific carbonylated proteins in hormonal- and light-dependent processes occurring in seeds is

  18. The contribution of germinal mosaicism to human aneuploidy.

    Science.gov (United States)

    Ghevaria, Harita; SenGupta, Sioban; Sarna, Urvashi; Sargeant, Susannah; Serhal, Paul; Delhanty, Joy

    2014-01-01

    Germinal mosaicism in a parent is considered to be a rare cause of aneuploidy in the offspring. The aim of this study was to assess the incidence of pre-meiotic errors, indicative of germinal mosaicism, leading to aneuploidy compared with those that occur at meiosis I. The material consisted of 126 oocytes, unexposed to sperm, donated by 57 women with an average maternal age of 35. The oocytes were at various stages of maturity and were analysed by array comparative genomic hybridisation. Of these, 102 gave conclusive results, comprising 47 that were immature, at the germinal vesicle (GV) or metaphase I stage (MI); 34 complete metaphase II-first polar body (MII-PB) complexes together with 21 incomplete complexes. Oocytes at the GV or MI stage provide direct evidence of pre-meiotic aneuploidy. Complete MII-PB complexes with the expected reciprocal gains/losses provide information on MI errors; those with non-reciprocal gains have pre-meiotic errors. Overall, 29 oocytes were aneuploid, and the source of the error was known for 21. In 8 (from 7 women) the error was pre-meiotic consisting of 4 MI oocytes and 4 MII-PB complexes with non-reciprocal gains. The remaining 13 were the result of errors at meiosis I. Although pre-meiotic errors occurred in only 10% of informative oocytes, most notable was the fact that for those oocytes where the source of the error was known, 38% were caused by germinal mosaicism compared with 62% that were the outcome of a meiosis I error. None of the women with germinal mosaicism were infertile.

  19. Proteomic Analysis of Lettuce Seed Germination and Thermoinhibition by Sampling of Individual Seeds at Germination and Removal of Storage Proteins by Polyethylene Glycol Fractionation1

    Science.gov (United States)

    Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-01-01

    Germination and thermoinhibition in lettuce (Lactuca sativa ‘Jianyexianfeng No. 1’) seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (P ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. PMID:25736209

  20. Maternal habitat affects germination requirements of Anabasis setifera, a succulent shrub of the Arabian deserts

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    Ali El-Keblawy

    2016-03-01

    Full Text Available The effects of maternal habitat on light and temperature requirements during germination were assessed for the succulent desert shrub Anabasis setifera. Seeds were collected from the Mediterranean habitats of Egypt and the hyper-arid subtropical habitats of the United Arab Emirates (UAE. Seeds from the two populations were germinated in three temperature treatments in both a light/dark regime and continuous darkness. Seeds from the Egyptian population germinated significantly greater and faster than those of UAE. Seeds stored for four months at room temperatures have little dormancy and germinate at wide range of temperatures and light conditions, but seeds stored four months in the natural habitat lost their ability to germinate and rotted 10 days after incubation. The germination response to temperature depended on the habitat type. Seeds of the Egyptian population attained a significantly greater germination at lower temperatures, compared with seeds from the UAE population, but there was no difference in germination between the two populations at higher temperatures. Germination of A. setifera was very fast; most seeds germinated within four days. These results reflect the adaptive strategy of germination in both populations, and may help explain the wide distribution of this species in different climatic regions.

  1. Effect of Salinity on Germination and Seedling Growth of Four Medicinal Plants

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    A Dadkhah

    2012-07-01

    Full Text Available This experiment was conducted in germinator in order to study the effects of water potential on seed germination, rate of germination and seedlings growth of four medicinal plants (Coriandrum sativum, Plantago psyllium, Discorinia sophia and Portulaca oleracea. Four water potential inclouding distilled water as control (0, -0.37, -0.59 and –0.81 Mpa which made by different salts (NaCl, CaCl2 and NaCl+CaCl2 in 5 to 1 molar ratio. The experiment was carried out based on completly randomized design with six replications. Results showed that the effects of water potential, type of salt on germination percentage, rate of germination, root and shoot length were significant. With decreasing water potential, germination percentage and rate of germination declined but the response of plant were differ. Germination of Portulaca oleracea was not affected by decreasing water potential where as other significantly decreased. The effect of salt composition was significant on rate and percentage germination. The percentage of germination at lower water potential (–0.37 MPa which made by NaCl + CaCl2 significantly was higher than the same water potential made by only NaCl and CaCl2. Although, percentage and rate germination of Portulaca oleracea were not affected by different water potential, seedling growth of Portulaca oleracea significantly decreased.

  2. Enhancement of seed germination in Macaranga peltata for use in tropical forest restoration

    Institute of Scientific and Technical Information of China (English)

    Cassie R. Rodrigues; Bernard F. Rodrigues

    2014-01-01

    We used pre-sowing treatments viz., soaking seeds in concen-trated sulphuric acid (CSA), gibberellic acid (GA), combined treatment of CSA+GA and mechanical scarification to overcome seed dormancy and enhance synchronous germination of Macaranga peltata seeds. We analysed percent seed germination data by logistic regression and con-firmed that except in GA treatment, time and acid concentration together were crucial for enhancing germination. The combination treatment of CSA and GA resulted in higher percent germination (up to 74%) than either treatment used separately, but produced defective seedlings (26%). Mechanical scarification of seed coat had the greatest impact in enhanc-ing germination (78%) and reducing imbibition time (6 days) against the control (0%). Germination studies and SEM analysis confirmed that seed germination in M. peltata was inhibited by seed coat dormancy.

  3. Phytochrome Control of Germination of Rumex crispus L. Seeds Induced by Temperature Shifts.

    Science.gov (United States)

    Taylorson, R B; Hendricks, S B

    1972-12-01

    High germination of curly dock (Rumex crispus L.) seeds is evident after suitable imbibition and temperature shift treatment, but germination at constant temperatures fails without an input of far red-absorbing form of phytochrome. Preliminary imbibitions at high temperatures (30 C) sharply reduce germination induced by temperature shifts. High germination may be restored by low energies of red radiation, or by brief far red adequate for the photosteady state. Prolonged far red during imbibition also nullifies temperature shift-induced germination. After prolonged far red, high germination may be restored by red radiation of an energy dependent upon the duration of the far red treatment. The evidence supports the conclusion that dark germination induced by temperature shifts arises from the interaction of pre-existent far red-absorbing form of phytochrome in the mature seeds with the temperature shift.

  4. Germination dramatically increases isoflavonoid content and diversity in chickpea (Cicer arietinum L.) seeds.

    Science.gov (United States)

    Wu, Ziyun; Song, Lixia; Feng, Shengbao; Liu, Yuancai; He, Guangyuan; Yioe, Yoecelyn; Liu, Shao Quan; Huang, Dejian

    2012-09-05

    The effect of germination on bioactive components in legume seeds was investigated in terms of the antioxidant capacity and total phenolic contents. Germination increased the total phenolic content and antioxidant capacity of most seeds. Particularly in chickpea seeds, the isoflavone contents increased by over 100 fold, mainly due to the increase of formononetin and biochanin A level. As a result, these two compounds were conveniently isolated from the germinated seeds in preparative scale and structurally confirmed by UV-vis, ESI-MS, and (1)H NMR spectroscopies. Isoflavonoid fingerprints analyzed by HPLC-PDA and LC-ESI-MS demonstrated that germination could significantly increase isoflavonoids diversity. Twenty-five isoflavonoids were detected and identified tentatively. These include 20 isoflavones, 2 isoflavanones, and 3 pterocarpan phytoalexins. Total isoflavonoid content of germinated chickpea was approximately 5-fold of that of germinated soybean. Our findings suggest that the germinated chickpea seeds could serve as a promising functional food rich in isoflavonoids.

  5. BIOSECURITY FOR REDUCING OCHRATOXIN A PRODUCTIVITY AND THEIR IMPACT ON GERMINATION AND ULTRASTRUCTURES OF GERMINATED WHEAT GRAINS

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    M.M.

    2012-08-01

    Full Text Available Ochratoxin A (OTA is a secondary metabolite of some fungi that causes very serious problems for plants, animals and humans. Various microorganisms such as bacteria and microscopic fungi have been tested for their abilities to prevent ochratoxin A contamination or detoxify foods. In this study, Saccharomyces cerevisiae and Lactobacillus bulgaricus reduced OTA production by Aspergillus ochraceus to 40.88 µg/ml ( productivity 60.69% and 13.80 µg/ml (productivity 20.48% respectively compared with the control (67.35 µg/ml (productivity 100%. The results clearly indicated that the seed germinibility in the presence of OTA was decreased with increasing concentration, whereas the germinibility was uncompletely ceased at high concentration (67.35 µg/ml of OTA. The maximum amount of germination was observed in control (without OTA treatment and at low concentration (13.80 µg/ml within 4 days. Antioxidant enzymes catalase and peroxidase decreased in germinated grains treated with OTA. Catalase was 18.12 U/ml in grains treated with low concentration (13.80 µg/ml of OTA while at high concentration (67.35 µg/ml, it was 12.23 U/ml compared with the control (20.33 U/ml. On the other hand, peroxidase decreased only in germinated grains treated with high concentration of OTA. The ultrastructural studies indicate that there were dramatic differences between the cells of root system of wheat seedlings of grains treated and untreated with the OTA. Cell ultrastructures of treated grains with OTA showed that the cytoplasmic membrane collapses away from the cell wall. Plasmodesmata threads were appeared in untreated cells but not formed in treated cells.

  6. Seed germination strategies: an evolutionary trajectory independent of vegetative functional traits

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    Gemma eHoyle

    2015-10-01

    Full Text Available 1.Seed germination strategies vary dramatically among species but relatively little is known about how germination traits correlate with other elements of plant strategy systems. Understanding drivers of germination strategy is critical to our understanding of the evolutionary biology of plant reproduction.2.We present a novel assessment of seed germination strategies focussing on Australian alpine species as a case study. We describe the distribution of germination strategies and ask whether these are correlated with, or form an independent axis to, other plant functional traits. Our approach to describing germination strategy mimicked realistic temperatures that seeds experience in situ following dispersal. Strategies were subsequently assigned using an objective clustering approach. We hypothesised that two main strategies would emerge, involving dormant or non-dormant seeds, and that while these strategies would be correlated with seed traits (e.g. mass or endospermy they would be largely independent of vegetative traits when analysed in a phylogenetically structured manner. 3.Across all species, three germination strategies emerged. The majority of species postponed germination until after a period of cold, winter-like temperatures indicating physiological and/or morphological dormancy mechanisms. Other species exhibited immediate germination at temperatures representative of those at dispersal. Interestingly, seeds of an additional 13 species 'staggered' germination over time. Germination strategies were generally conserved within families. Across a broad range of ecological traits only seed mass and endospermy showed any correlation with germination strategy when phylogenetic relatedness was accounted for; vegetative traits showed no significant correlations with germination strategy. The results indicate that germination traits correlate with other aspects of seed ecology but form an independent axis relative to vegetative traits.

  7. Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation.

    Science.gov (United States)

    Wang, Wei-Qing; Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-04-01

    Germination and thermoinhibition in lettuce (Lactuca sativa 'Jianyexianfeng No. 1') seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (Pgermination treatment. Nineteen proteins increasing and one protein decreasing in abundance during germination had higher abundance in germinated 15°C, 15°C after imbibition at 25°C for 48 h, and 25°C in KNO3 seeds than in ungerminated 25°C seeds. Gene expression of 12 of those proteins correlated well with the protein accumulation. Methionine metabolism, ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition.

  8. A Gompertz regression model for fern spores germination

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    Gabriel y Galán, Jose María

    2015-06-01

    Full Text Available Germination is one of the most important biological processes for both seed and spore plants, also for fungi. At present, mathematical models of germination have been developed in fungi, bryophytes and several plant species. However, ferns are the only group whose germination has never been modelled. In this work we develop a regression model of the germination of fern spores. We have found that for Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei and Polypodium feuillei species the Gompertz growth model describe satisfactorily cumulative germination. An important result is that regression parameters are independent of fern species and the model is not affected by intraspecific variation. Our results show that the Gompertz curve represents a general germination model for all the non-green spore leptosporangiate ferns, including in the paper a discussion about the physiological and ecological meaning of the model.La germinación es uno de los procesos biológicos más relevantes tanto para las plantas con esporas, como para las plantas con semillas y los hongos. Hasta el momento, se han desarrollado modelos de germinación para hongos, briofitos y diversas especies de espermatófitos. Los helechos son el único grupo de plantas cuya germinación nunca ha sido modelizada. En este trabajo se desarrolla un modelo de regresión para explicar la germinación de las esporas de helechos. Observamos que para las especies Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei y Polypodium feuillei el modelo de crecimiento de Gompertz describe satisfactoriamente la germinación acumulativa. Un importante resultado es que los parámetros de la regresión son independientes de la especie y que el modelo no está afectado por variación intraespecífica. Por lo tanto, los resultados del trabajo muestran que la curva de Gompertz puede representar un modelo general para todos los helechos leptosporangiados

  9. Germination of radish seeds (Raphanus sativus treated with homeopathic drugs

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    Solange Monteiro de Toledo Piza Gomes Carneiro

    2011-09-01

    Full Text Available The radish is a short cycle crop, since it is harvested at 25-30 days after direct sowing. Under the economic point of view it is an important species, but there are few studies on germination of radish seeds. The objective of this study was to evaluate the effect of high diluted substances on the germination of radish seeds. The trial was conducted at the Agricultural Research Institute of Paraná (IAPAR in Londrina / Paraná. It was used a pesticide free cultivar named Cometa. The treatments were: Bryonia, hydroalcoholic solution, Arnica montana, Cina and Lupine + Oat, all of them diluted and agitated at 9x; distilled water and agitated distilled water were used as controls. The mother tincture of Lupine + Oat was prepared from plants collected at the experimental station of IAPAR in Londrina. The mother tincture and all treatments were prepared according to the guidelines in the Brazilian Homeopathic Pharmacopeia, Part I [1]. The agitations of the treatments were made by a mechanical equipment, model Denise 10-50 manufactured by Autic. The water was distilled the day before preparing the treatments. The experiment was performed with 300 seeds per treatment. The seeds were placed in gerbox with germitest paper, and 50 gerbox were used per treatment, with six seeds in each gerbox. The germitest papers were moistened with the treatments and the seeds were soaked for 2 hours previously set up the experiment. The substances in high dilutions were agitated 100 times on the machine before soaking the seeds and moistening the germitest paper. The experimental design was entirely randomized and the gerbox were kept at the bench at the Laboratory of Plant Protection of IAPAR. A person not involved in conduct of the experiment coded (blinded the treatments solutions with a random letter code. The code was kept secret until all measurements and data processing were finished. Seeds were observed daily for germination and counted only those

  10. Germination Response of MR 219 Rice Variety to Different Exposure Times and Periods of 2450 MHz Microwave Frequency

    OpenAIRE

    Daryush Talei; Alireza Valdiani; Mahmood Maziah; Mohammad Mohsenkhah

    2013-01-01

    Germination is a key process in plants' phenological cycles. Accelerating this process could lead to improvment of the seedling growth as well as the cultivation efficiency. To achieve this, the effect of microwave frequency on the germination of rice seeds was examined. The physiological feedbacks of the MR 219 rice variety in terms of seed germination rate (GR), germination percentage (GP), and mean germination time (MGT) were analyzed by exposing its seeds to 2450 MHz of microwave frequenc...

  11. Transcriptional regulatory programs underlying barley germination and regulatory functions of Gibberellin and abscisic acid

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    Lin Li

    2011-06-01

    Full Text Available Abstract Background Seed germination is a complex multi-stage developmental process, and mainly accomplished through concerted activities of many gene products and biological pathways that are often subjected to strict developmental regulation. Gibberellins (GA and abscisic acid (ABA are two key phytohormones regulating seed germination and seedling growth. However, transcriptional regulatory networks underlying seed germination and its associated biological pathways are largely unknown. Results The studies examined transcriptomes of barley representing six distinct and well characterized germination stages and revealed that the transcriptional regulatory program underlying barley germination was composed of early, late, and post-germination phases. Each phase was accompanied with transcriptional up-regulation of distinct biological pathways. Cell wall synthesis and regulatory components including transcription factors, signaling and post-translational modification components were specifically and transiently up-regulated in early germination phase while histone families and many metabolic pathways were up-regulated in late germination phase. Photosynthesis and seed reserve mobilization pathways were up-regulated in post-germination phase. However, stress related pathways and seed storage proteins were suppressed through the entire course of germination. A set of genes were transiently up-regulated within three hours of imbibition, and might play roles in initiating biological pathways involved in seed germination. However, highly abundant transcripts in dry barley and Arabidopsis seeds were significantly conserved. Comparison with transcriptomes of barley aleurone in response to GA and ABA identified three sets of germination responsive genes that were regulated coordinately by GA, antagonistically by ABA, and coordinately by GA but antagonistically by ABA. Major CHO metabolism, cell wall degradation and protein degradation pathways were up

  12. Can heavy metal pollution defend seed germination against heat stress? Effect of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination under high temperature.

    Science.gov (United States)

    Deng, Benliang; Yang, Kejun; Zhang, Yifei; Li, Zuotong

    2016-09-01

    Heavy metal pollution, as well as greenhouse effect, has become a serious threat today. Both heavy metal and heat stresses can arrest seed germination. What response can be expected for seed germination under both stress conditions? Here, the effects of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination were investigated at 20 °C and 40 °C. Compared with 20 °C, heat stress induced thermodormancy. However, this thermodormancy could be significantly alleviated by the addition of a low concentration of heavy metals. Heavy metals, as well as heat stress induced H2O2 accumulation in germinating seeds. Interestingly, this low concentration of heavy metal that promoted seed germination could be partly blocked by DMTU (a specific ROS scavenger), irrespective of temperature. Accordingly, H2O2 addition reinforced this promoting effect on seed germination, which was induced by a low concentration of heavy metal. Furthermore, we found that the NADPH oxidase derived ROS was required for seed germination promoted by the heavy metals. Subsequently, treatment of seeds with fluridone (a specific inhibitor of ABA) or ABA significantly alleviated or aggravated thermodormancy, respectively. However, this alleviation or aggravation could be partly attenuated by a low concentration of heavy metals. In addition, germination that was inhibited by high concentrations of heavy metals was also partly reversed by fluridone. The obtained results support the idea that heavy metal-mediated ROS and hormone interaction can finally affect the thermodormancy release or not.

  13. Alicyclobacillus acidoterrestris: new methods for inhibiting spore germination.

    Science.gov (United States)

    Bevilacqua, A; Sinigaglia, M; Corbo, M R

    2008-07-15

    For a long period the thermal processing has been considered as the only way to reduce the initial spore number of Alicyclobacillus acidoterrestris and prevent the spoilage of acidic beverage. New methods, however, were proposed by the literature to control spore germination both in laboratory media and in real systems. After a brief introduction on the impact of A. acidoterrestris in food microbiology and a description of enumeration methods and heat processing applied by the juices manufactures, a review of innovative approaches to inhibit and/or control spore germination is proposed. In particular, this paper focuses on two different topics; the 1st is the use of some natural compounds (monolaurin, lysozyme, nisin and essential oils) or some chemicals, conventional (like sodium-benzoate, organic acids, surfactants and chlorine dioxide) or not conventional (chlorine dioxide as gas). The 2nd topic is a description of some innovative methods to reduce the initial spore number (high hydrostatic and homogenisation pressures, radiation and microwaves).

  14. Effect of seed stimulation on germination and sugar beet yield

    Science.gov (United States)

    Prośba-Białczyk, U.; Szajsner, H.; Grzyś, E.; Demczuk, A.; Sacała, E.; Bąk, K.

    2013-03-01

    Germination and sugar beet yield after seed stimulation were investigated. The seeds came from the energ'hill technology and were subject to laser irradiation. The experiments were conducted in the laboratory and field conditions. Lengthening of germinal roots and hypocotyls was observed. A positive effect of the stimulation on the morphological features was observed for the Eh seeds and laser irradiation applied in a three-fold dose. The energ'hill seeds exhibited a significantly higher content of carotenoids in seedlings and an increase in the content of chlorophylls. Laser light irradiation favourably modified the ratio of chlorophyll a to b. The leaves and roots of plants developed from the energ'hill and irradiated seeds were characterized by higher dry matter content thanin non-stimulated seeds. Seed stimulation had a positive influence on yielding and the saccharose content.

  15. Proteomics and posttranslational proteomics of seed dormancy and germination.

    Science.gov (United States)

    Rajjou, Loïc; Belghazi, Maya; Catusse, Julie; Ogé, Laurent; Arc, Erwann; Godin, Béatrice; Chibani, Kamel; Ali-Rachidi, Sonia; Collet, Boris; Grappin, Philippe; Jullien, Marc; Gallardo, Karine; Job, Claudette; Job, Dominique

    2011-01-01

    The seed is the dispersal unit of plants and must survive the vagaries of the environment. It is the object of intense genetic and genomic studies because processes related to seed quality affect crop yield and the seed itself provides food for humans and animals. Presently, the general aim of postgenomics analyses is to understand the complex biochemical and molecular processes underlying seed quality, longevity, dormancy, and vigor. Due to advances in functional genomics, the recent past years have seen a tremendous progress in our understanding of several aspects of seed development and germination. Here, we describe the proteomics protocols (from protein extraction to mass spectrometry) that can be used to investigate several aspects of seed physiology, including germination and its hormonal regulation, dormancy release, and seed longevity. These techniques can be applied to the study of both model plants (such as Arabidopsis) and crops.

  16. Pollen germination and pollen tube growth in ZP maize lines

    Directory of Open Access Journals (Sweden)

    Cerović Radosav

    2014-01-01

    Full Text Available The study was conducted on the in vitro pollen germination at 26°, 28°, 32° and 35°C for 24h of male parental lines, pollen tube growth in vivo in cross pollination of female and male parental lines that make couples in four hybrids: ZP 504 su (♀ ZPPL 51 × ♂ ZPPL 67; ZP 677 (♀ ZPPL 17 × ♂ ZPPL 201; ZP 704 (♀ ZPPL 109 × ♂ ZPPL 79, ZP 611 k (♀ ZPPL 126 × ♂ ZPPL 105, and the open pollination of female parental lines of the above mentioned hybrids. Pollen germination in vitro and pollen tube growth dynamics in vivo showed different genotypic specificities with the tests applied. The obtained results were discussed in the context of reproductive biology of ZP maize lines and aimed to create the preconditions for successful management and direction of the process in practice - seed production in certain environmental conditions.

  17. Algebraic determination of the evolutionary stable germination fraction.

    Science.gov (United States)

    Valleriani, Angelo

    2005-11-01

    In this article, we consider a bet-hedging model with density dependence for germination behavior of dormant seeds. We show how to compute accurate values of the evolutionary stable germination fraction using a method based on expansion around the average seed bank size. The expansion is made up to the fourth order and is expressed in terms of the first four moments of the distribution of the year-to-year variation in the average yield per adult plant. This method leads to a simple algebraic equation, which can be solved without recurring to simulations of the seed bank dynamics. We first show the analytical derivation under general assumptions about the effect of density dependence. We then test our results with a numerical analysis where an explicit form of the density dependence has been taken.

  18. Effect of Magnetic Field on Seed Germination of Wheat

    Directory of Open Access Journals (Sweden)

    Hussein Falaihj HUSSEIN

    2012-12-01

    Full Text Available The current project studies the influence of the exposure rate of the magnetic field (50 mT/time upon germination in wheat seeds. Magnetic treatment involved the application of three different exposure rates (0.5, 1, 2 h respectively. The effect of the exposure rate on the root growth, radicle growth and protein percentage are discussed and statistical significance analysis is assessed for the differences between the average values of samples and controls. The variable magnetic field of exposure rate (50 mT/0.5h is a very significant factor in influencing the germination process of wheat seeds. It is observed that the root length, radicle length and the protein percentage increase up to 10, 14 and 8 % respectively.

  19. [Characteristics of seed germination of rare plant species Reaumuria trigyna in west Ordos].

    Science.gov (United States)

    Zhang, Ying-juan; Wang, Yu-shan; Li, Qing-feng

    2008-12-01

    Reaumuria trigyna is a relic species in the desert shrubbery vegetation in arid regions of northwestern China, and plays an important role in the maintenance of the stability of desert vegetation. In this paper, the seed traits and germination strategy of R. trigyna under different environmental conditions, e.g., light, temperature, soil moisture, and sand bury, were investigated. The results showed that R. trigyna seed had high vigor and high germination rate, and endured reserve. The seed could germinate either in light or in darkness, and the optimal temperature for germination was 20 degrees C - 25 degrees C or 15 degrees C/25 degrees C, with the germination rate being 93%. The seed could start to germinate when soil moisture content was 2%, and the germination rate was the highest (89%) when the moisture content was 12%. The optimal sand burial depth of R. trigyna seed was 1 cm, and no seed would germinate when the sand burial depth was >5 cm. Sand burial depth had significant effects on the seedling's emergence percentage and growth height, but lesser effects on seedling' s mass. Soil moisture and sand burial depth were the main environmental factors limiting the seed germination and seedling emergence of R. trigyna. The high seed germination rate of R. trigyna enhanced the survival risk of its seedlings, which was unfavorable to its handling with the extreme changes of desert environment. Such a character of R. trigyna seed was one of the factors causing the species endangered.

  20. Seed germination of three species of Fabaceae typical of seasonally dry forest

    Directory of Open Access Journals (Sweden)

    Daniel Meira Arruda

    2015-06-01

    Full Text Available This study evaluates seeds germination of Anadenanthera colubrina, Acacia polyphylla and Bauhinia cheilantha, typical species of deciduous forests. Seeds were submitted to pre-germination treatments and attack of native insects. The seeds of each species were grouped in: seeds scarified with sandpaper; seeds immersed in water heated to 70 °C, seeds with signs of attack by herbivore insects and the control group. The largest proportion of germinated seeds occurred in the first week of incubation and germination peak, ranged from first to third day. All groups of A. polyphylla and B.cheilantha showed high germination rate (> 90%, being reduced only when seeds were attacked by insects (< 25%. Mechanic scarification was efficient in A. polyphylla by enhancing germination to maximum (100% and accelerating germination. A. colubrina showed no difference among groups, and germination rate was lower (< 50%, which was attributed to infestation by fungi, commonly reported in this species and apparently independent of usual hygiene procedures. Finally, except the fungi infestation in A. colubrina, evaluated species were independent of pre-germination treatment to obtain a high rate of germination.

  1. Are cactus growth forms related to germination responses to light? A test using Echinopsis species

    Science.gov (United States)

    Ortega-Baes, Pablo; Aparicio-González, Mónica; Galíndez, Guadalupe; del Fueyo, Patricia; Sühring, Silvia; Rojas-Aréchiga, Mariana

    2010-05-01

    In this study, we investigated the effect of light regimen (white light vs. darkness) on the germination of 12 species of the Echinopsis genus (tribe Trichocereeae, Cactaceae). This genus presents a variety of growth forms and relatively small and uniform seed size. These traits allowed us to test, within the same linage and removing seed mass effect, the hypothesis that the germination response to light (indifferent to light or positive photoblastic) is related to growth form. Our results reject this hypothesis since no seeds germinated in darkness, so all of the species can be classified as being positively photoblastic. The proportion of seed germination with white light was significantly different among cactus growth forms. Columnar cacti (arborescent, creeping and short) showed a greater proportion of seed germination than barrel and globose cacti. The germination rate differed among growth forms and species. At constant temperatures, creeping columnar cacti presented a significantly higher germination rate than the other growth forms. With alternating temperatures, columnar cacti showed higher germination rates than the other growth forms. The low proportion of seeds that germinated for some species indicates that they show seed dormancy. Our results suggest that germination responses to light in the cactus family could be related to seed mass and phylogenetic constraints.

  2. Seed germination in response to chemicals: effect of nitrogen and pH in the media.

    Science.gov (United States)

    Pérez-Fernández, M A; Calvo-Magro, E; Montanero-Fernández, J; Oyola-Velasco, J A

    2006-01-01

    Seed germination generally presents a peak in the next growing season after a fire. Among other factors associated with fire are the increase of soil nitrogen and changes in the pH of the soil. In this study, we addressed the question, whether or not the germination response of eight species is linked with the increase in pH and nitrogenous compounds in the germination media? We assessed the separate and combined effects of nitrogenous compounds and pH on the percentage and rate of germination of seeds of Medicago arabica (L.) Hudson, Epilobium hirsutum L., Foeniculum vulgare Miller, Daucus carota L., Thapsia villosa L., Cynosurus cristatus L., Dactylis glomerata L. and Rumex crispus L. All these species are well represented in the Mediterranean ecosystems of the central-west Spain. Water and CaCl2 were used as controls. Nitrogenous compounds increased percent germination (level) and rate in three of the species studied. High pH negatively affected the germination rate of seeds from most species, but had no effect on the per cent germination of any of the species. The higher concentration of the nutritious solutions affected negatively the germination level and rate. The different germination responses of seeds of the studied species could not be exclusively attributed to pH values in the media, whereas the amount and form of Nitrogen in the media has a greater effect on it. These differences in germination are species dependent.

  3. [Studies on biological characteristics and germination conditions of Thladiantha dubia seeds].

    Science.gov (United States)

    Zhao, Chun-Ying; Su, Zhan-Hui; Mao, Xiao-Xia; Tong, Ji-Ming

    2013-07-01

    To study the biological characteristics and find out the optimum condition for germination of seed of Thladiantha dubia Bunge for its standardized culturing. The weight per 1 000 seeds, seed moisture content and seed viability were determined. The biological characteristics were studied and germination conditions of seed of T. dubia were tested under following conditions: different seed soaking time, different temperatures (15, 20, 25, 30, 35 degrees C) and different irradiation time (0, 5, 10, 15, 20 min). The average length, width and thickness of T. Dubia seed were 4.96, 3.25 and 1.08 mm, respectively. The weight per 1 000 seeds was 14.03 g; the seed moisture content was 10.10%; the seed viability was 90.33%. Under the same condition of light, temperature and other factors, the seed germination percentage and germination energy were the highest after seed soaking 24 h. The suitable temperature range of seeds was form 25 degrees C to 35 degrees C. Under different irradiation time, the seed germination percentage and germination energy were the highest after irradiation 10 min. In different germinating beds, the seeds germination percentage and germination energy were the highest on paper (TP), which was 89.33%. The optimum condition for the germination of the seed of T. dubia is seed soaking 12 h, irradiation 10 min, 25-30 degrees C on filter paper.

  4. Structural requirements of strigolactones for germination induction and inhibition of Striga gesnerioides seeds.

    Science.gov (United States)

    Nomura, Saki; Nakashima, Hitomi; Mizutani, Masaharu; Takikawa, Hirosato; Sugimoto, Yukihiro

    2013-06-01

    Structure-activity relationship studies of strigolactones and Striga gesnerioides seed germination revealed strict structural requirements for germination induction and a new function of the plant hormones as germination inhibitors. Stereoisomers of the naturally occurring strigolactones, strigol, sorgolactone, orobanchol, sorgomol and 5-deoxystrigol, 36 in total, were prepared and screened for the ability to induce and/or inhibit the germination of Striga hermonthica and Striga gesnerioides seeds collected from mature plants that parasitized on sorghum and cowpea, respectively. All of the compounds induced S. hermonthica seed germination, albeit displayed differential activities. On the other hand, only a limited number of the compounds induced significant germination in S. gesnerioides, thus indicating strict structural requirements. Strigolactones inducing high germination in S. gesnerioides induced low germination in S. hermonthica. Strigolactones with the same configuration at C3a, C8b and C2' as that in 5-deoxystrigol (9a) induced high germination of S. hermonthica seeds, but most of them inhibited the germination of S. gesnerioides. The differential response of S. gesnerioides to strigolactones may play an important role in the survival of the species. However, the compounds could be used as means of control if mixed cropping of cowpea and sorghum is adopted.

  5. Control of macaw palm seed germination by the gibberellin/abscisic acid balance.

    Science.gov (United States)

    Bicalho, E M; Pintó-Marijuan, M; Morales, M; Müller, M; Munné-Bosch, S; Garcia, Q S

    2015-09-01

    The hormonal mechanisms involved in palm seed germination are not fully understood. To better understand how germination is regulated in Arecaceae, we used macaw palm (Acrocomia aculeata (Jacq.) Lodd. Ex Mart.) seed as a model. Endogenous hormone concentrations, tocopherol and tocotrienol and lipid peroxidation during germination were studied separately in the embryo and endosperm. Evaluations were performed in dry (D), imbibed (I), germinated (G) and non-germinated (NG) seeds treated (+GA3 ) or not treated (control) with gibberellins (GA). With GA3 treatment, seeds germinated faster and to a higher percentage than control seeds. The +GA3 treatment increased total bioactive GA in the embryo during germination relative to the control. Abscisic acid (ABA) concentrations decreased gradually from D to G in both tissues. Embryos of G seeds had a lower ABA content than NG seeds in both treatments. The GA/ABA ratio in the embryo was significantly higher in G than NG seeds. The +GA3 treatment did not significantly affect the GA/ABA ratio in either treatment. Cytokinin content increased from dry to germinated seeds. Jasmonic acid (JA) increased and 1-aminocyclopropane-1-carboylic acid (ACC) decreased after imbibition. In addition, α-tocopherol and α-tocotrienol decreased, while lipid peroxidation increased in the embryo during germination. We conclude that germination in macaw palm seed involves reductions in ABA content and, consequently, increased GA/ABA in the embryo. Furthermore, the imbibition process generates oxidative stress (as observed by changes in vitamin E and MDA).

  6. Photoinhibition of germination in grass seed--implications for prairie revegetation.

    Science.gov (United States)

    Mollard, Federico P O; Naeth, M Anne

    2014-09-01

    Germination photoinhibition is not a recognized cause of revegetation failure; yet prolonged sunlight exposure can inhibit germination of several grass species. This research addressed susceptibility to photoinhibition of selected native grass species used to restore Canadian prairies, and reclamation treatments to alter environmental conditions in order to release seeds from photoinhibition. Under laboratory conditions effects of photoinhibition were tested on the ability of seeds to germinate at low water potential and effects of daily alternating temperatures and nitrates to break photoinhibition. Whether surficial mulch can release seeds from photoinhibition was assessed in a field experiment. Germination photoinhibition was evident in Festuca hallii and Koeleria macrantha seeds even under very low irradiances. The prolonged exposure to light decreased germination rates and ability of seeds to germinate at low water potentials. Daily fluctuating temperatures released a fraction of Bromus carinatus and Elymus trachycaulus seeds from photoinhibition yet did not improve F. hallii or K. macrantha germinability. Nitrates failed to break seed photoinhibition in all species tested. In the field experiment, mulched F. hallii seeds (covered with an erosion control blanket) showed a tenfold increase in germination percentages relative to seeds exposed to direct sunlight, indicating the facilitative effects of mulching on attenuation of the light environment. We conclude that germination photoinhibition as a cause of emergence failures in land reclamation where seed is broadcast or shallow seeded should be recognized and germination photoinhibition included in the decision making process to select revegetation seeding techniques.

  7. Reduced seed germination in Arabidopsis over-expressing SWI/SNF2 ATPase genes.

    Science.gov (United States)

    Leeggangers, Hendrika A C F; Folta, Adam; Muras, Aleksandra; Nap, Jan-Peter; Mlynarova, Ludmila

    2015-02-01

    In the life of flowering plants, seed germination is a critical step to ensure survival into the next generation. Generally the seed prior to germination has been in a dormant state with a low rate of metabolism. In the transition from a dormant seed to a germinating seed, various epigenetic mechanisms play a regulatory role. Here, we demonstrate that the over-expression of chromatin remodeling ATPase genes (AtCHR12 or AtCHR23) reduced the frequency of seed germination in Arabidopsis thaliana up to 30% relative to the wild-type seeds. On the other hand, single loss-of-function mutations of the two genes did not affect seed germination. The reduction of germination in over-expressing mutants was more pronounced in stress conditions (salt or high temperature), showing the impact of the environment. Reduced germinations upon over-expression coincided with increased transcript levels of seed maturation genes and with reduced degradation of their mRNAs stored in dry seeds. Our results indicate that repression of AtCHR12/23 gene expression in germinating wild-type Arabidopsis seeds is required for full germination. This establishes a functional link between chromatin modifiers and regulatory networks towards seed maturation and germination.

  8. Modulation of Anti-Oxidation Ability by Proanthocyanidins during Germination of Arabidopsis thaliana Seeds

    Institute of Scientific and Technical Information of China (English)

    Li-Guo Jia; Zi-Wei Sheng; Wei-Feng Xu; Ying-Xuan Li; Ying-Gao Liu; Yi-Ji Xia; Jian-Hua Zhang

    2012-01-01

    Proanthocyanidins (PAs) as the end products of flavonoid biosynthetic pathway mainly accumulate in seed coat but their biological function is largely unknown.We studied the anti-oxidation ability in seed coat and germination changes under externally applied oxidative stresses in PAs-deficient mutants of Arabidopsis.Germination of PAs-deficient mutant seeds was faster than that of wild-type under low or no oxidative stress,suggesting a PAs-induced inhibition of germination.When the applied oxidative stress was high,germination of PAs-deficient mutants was lower than that of wild-type,suggesting a loss of PAs-related anti-oxidation ability in the mutants.Using ABA signaling mutants,our studies demonstrated that both ABA signaling pathway and PAs were important for the response to serve oxidative stress during seed germination.However,the discrepancy of the response between abi mutants and PAs mutants to oxidative stress suggests that ABA signaling pathway may not play a major role in PAs' action in alleviating oxidative stress.Under low or no oxidative stress,germination was mainly determined by the ABA content in seed and the PAs-deficient mutant seeds germinated faster due to their lower ABA content than wild-type.However,oxidative injury inhibited germination when PAs-deficient seeds germinated under high oxidative stress.Wild-type exhibited higher germination under the high oxidative stress due to the PAs' anti-oxidation ability.Oxidative stress applied externally led to changes in endogenous PAs contents that coincided with the expression changes of PAs biogenesis genes.PAs modulated the activities of some key enzymes that controlled the levels of reactive oxygen species and the anti-oxidation capacity during the seed germination.This work suggests that PAs contribute to the adaptive mechanism that helps germination under environmental stresses by playing dual roles in both germination control and anti-oxidation reaction.

  9. In vivo imaging of germinal centres reveals a dynamic open structure.

    Science.gov (United States)

    Schwickert, Tanja A; Lindquist, Randall L; Shakhar, Guy; Livshits, Geulah; Skokos, Dimitris; Kosco-Vilbois, Marie H; Dustin, Michael L; Nussenzweig, Michel C

    2007-03-01

    Germinal centres are specialized structures wherein B lymphocytes undergo clonal expansion, class switch recombination, antibody gene diversification and affinity maturation. Three to four antigen-specific B cells colonize a follicle to establish a germinal centre and become rapidly dividing germinal-centre centroblasts that give rise to dark zones. Centroblasts produce non-proliferating centrocytes that are thought to migrate to the light zone of the germinal centre, which is rich in antigen-trapping follicular dendritic cells and CD4+ T cells. It has been proposed that centrocytes are selected in the light zone on the basis of their ability to bind cognate antigen. However, there have been no studies of germinal-centre dynamics or the migratory behaviour of germinal-centre cells in vivo. Here we report the direct visualization of B cells in lymph node germinal centres by two-photon laser-scanning microscopy in mice. Nearly all antigen-specific B cells participating in a germinal-centre reaction were motile and physically restricted to the germinal centre but migrated bi-directionally between dark and light zones. Notably, follicular B cells were frequent visitors to the germinal-centre compartment, suggesting that all B cells scan antigen trapped in germinal centres. Consistent with this observation, we found that high-affinity antigen-specific B cells can be recruited to an ongoing germinal-centre reaction. We conclude that the open structure of germinal centres enhances competition and ensures that rare high-affinity B cells can participate in antibody responses.

  10. Modulation of anti-oxidation ability by proanthocyanidins during germination of Arabidopsis thaliana seeds.

    Science.gov (United States)

    Jia, Li-Guo; Sheng, Zi-Wei; Xu, Wei-Feng; Li, Ying-Xuan; Liu, Ying-Gao; Xia, Yi-Ji; Zhang, Jian-Hua

    2012-03-01

    Proanthocyanidins (PAs) as the end products of flavonoid biosynthetic pathway mainly accumulate in seed coat but their biological function is largely unknown. We studied the anti-oxidation ability in seed coat and germination changes under externally applied oxidative stresses in PAs-deficient mutants of Arabidopsis. Germination of PAs-deficient mutant seeds was faster than that of wild-type under low or no oxidative stress, suggesting a PAs-induced inhibition of germination. When the applied oxidative stress was high, germination of PAs-deficient mutants was lower than that of wild-type, suggesting a loss of PAs-related anti-oxidation ability in the mutants. Using ABA signaling mutants, our studies demonstrated that both ABA signaling pathway and PAs were important for the response to serve oxidative stress during seed germination. However, the discrepancy of the response between abi mutants and PAs mutants to oxidative stress suggests that ABA signaling pathway may not play a major role in PAs' action in alleviating oxidative stress. Under low or no oxidative stress, germination was mainly determined by the ABA content in seed and the PAs-deficient mutant seeds germinated faster due to their lower ABA content than wild-type. However, oxidative injury inhibited germination when PAs-deficient seeds germinated under high oxidative stress. Wild-type exhibited higher germination under the high oxidative stress due to the PAs' anti-oxidation ability. Oxidative stress applied externally led to changes in endogenous PAs contents that coincided with the expression changes of PAs biogenesis genes. PAs modulated the activities of some key enzymes that controlled the levels of reactive oxygen species and the anti-oxidation capacity during the seed germination. This work suggests that PAs contribute to the adaptive mechanism that helps germination under environmental stresses by playing dual roles in both germination control and anti-oxidation reaction.

  11. Study of Seed Germination by Soaking Methode of Cacao (Theobroma cacao L.

    Directory of Open Access Journals (Sweden)

    Sulistyani Pancaningtyas

    2014-12-01

    Full Text Available Study of germination methods conduct to get information about seed viability based on germination rate, percentage of germination and vigority. Germination methods was studied to get the efficiency and effectivity of germination, easy to handle, low costs with high vigority. Sand and gunny sack methods  for germination, need extensive place  and 3-4 days germination period after planting. This research will study the alternative of germination method with soaking. This method can be accelerating  germination rate and effectively place usage without decreasing the quality of cacao seedling.The research was done at Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institue. This research consist of two experiment was arranged based on factorial completely random design. First experiment will observed to compared germination rate and the second experiment will observed seedling quality between soaking and wet gunny sack germination method.The results showed that length of radicel on soaking method longer than wet gunny sack method. Growth of radicel started from 2 hours after soaking, moreover length of radicel at 4 hours after soaking have significant different value with gunny sack method. On 24 hours after soaking have 3,69 mm and 0,681 mm on wet gunny sack treatment. Except lengt of hipocotyl, there is not different condition between seedling that out came  from soaking and wet gunny sack method. Length of hipocotyl on 36 hours after soaking have 9,15 cm and significant different between wet gunny sack germination method that have 5,40 cm. Keywords : seed germination, soaking method, Theobroma cacao L., cocoa seedlings

  12. Nutritional assessment of barley, talbina and their germinated products

    Directory of Open Access Journals (Sweden)

    Mohamed kamal El-Sayed Youssef

    2013-02-01

    Full Text Available Talbina is a food product with high potential applications as a functional food. Talbina was prepared from two barley varieties namely: Giza126 and Giza130 by adding whole barley flour to water (1:10 w/v and (1:5 w/v for germinated barley then heating at  80° C for 5 minutes with continuous stirring until reaching a porridge like texture. The present investigation was carried out in an attempt to clearly the nutritional assessment of talbina as a functional food. The study included the determination of gross chemical composition, caloric value, mineral composition, vitamins composition and the amino acids composition. Meanwhile, computation of the chemical scores (CS and A/E ratios were carried out for raw, germinated barley, talbina, germinated talbina and commercial talbina. The data revealed that protein content of the all raw studied and processing treatments ranged from 8.75-18.34g/100g on dry weight basis. Besides, the all treatments recorded rather slight decrease in crude fat content. Likewise, ash and carbohydrates ranged between 2.29-2.86 and 73.40-82.66%, respectively. Whereas crude fiber had an increase after treatments and it ranged from 3.83-4.37%. On the other hand by making talbina iron, manganese, copper and zinc increased especially zinc, which recorded higher value than that recommended daily. Furthermore, germinated talbina130 recorded the highest amounts of vitamins B2, Nicotinic acid, B6 and folic acid. Moreover, the present study indicated that phenylalanine was the highest essential amino acid, followed by leucine.

  13. Fetal germinal matrix and intraventricular haemorrhage diagnosed by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, K.; Morioka, T.; Nishio, S.; Fukui, M. [Dept. of Neurosurgery, Kyushu Univ., Fukuoka (Japan); Mihara, F. [Dept. of Clinical Radiology, Kyushu Univ., Fukuoka (Japan); Nakayama, H. [Dept. of Paediatrics, Kyushu Univ., Fukuoka (Japan); Tsukimori, K. [Dept. of Obstetrics, Kyushu Univ., Fukuoka (Japan)

    2001-01-01

    Subependymal germinal matrix haemorrhage and intraventricular haemorrhage (GMIVH) is a common complication of delivery in preterm neonates but has rarely been observed in the fetus. We report two cases of GMIVH in fetuses of 36 weeks gestation, clearly demonstrated by antenatal MRI. In both cases progressive ventriculomegaly was observed, and ventriculoperitoneal shunts were placed at 19 and 6 months of age, respectively. Prenatal GMIVH may be a cause of congenital hydrocephalus, for which no aetiology has yet been found. (orig.)

  14. Desiccation effects on germination and vigor of King palm seeds

    OpenAIRE

    Martins Cibele C.; Bovi Marilene L. A.; Nakagawa João

    2003-01-01

    The desiccation tolerance of Archontophoenix alexandrae (Wendl. & Drude) seeds was determined and the most sensitive vigor test for assessing seed deterioration of this species was identified. Mature fruits were harvested in the palm collection of the Instituto Agronomico in Campinas, Brazil. Depulped fruits were transported in impermeable packages to the Faculdade de Agronomia in Botucatu, where the seeds were dried. As the seed moisture decreased, germination, seedling length, electrica...

  15. Fungal specificity bottlenecks during orchid germination and development.

    Science.gov (United States)

    Bidartondo, Martin I; Read, David J

    2008-08-01

    Fungus-subsidized growth through the seedling stage is the most critical feature of the life history for the thousands of mycorrhizal plant species that propagate by means of 'dust seeds.' We investigated the extent of specificity towards fungi shown by orchids in the genera Cephalanthera and Epipactis at three stages of their life cycle: (i) initiation of germination, (ii) during seedling development, and (iii) in the mature photosynthetic plant. It is known that in the mature phase, plants of these genera can be mycorrhizal with a number of fungi that are simultaneously ectomycorrhizal with the roots of neighbouring forest trees. The extent to which earlier developmental stages use the same or a distinctive suite of fungi was unclear. To address this question, a total of 1500 packets containing orchid seeds were buried for up to 3 years in diverse European forest sites which either supported or lacked populations of helleborine orchids. After harvest, the fungi associated with the three developmental stages, and with tree roots, were identified via cultivation-independent molecular methods. While our results show that most fungal symbionts are ectomycorrhizal, differences were observed between orchids in the representation of fungi at the three life stages. In Cephalanthera damasonium and C. longifolia, the fungi detected in seedlings were only a subset of the wider range seen in germinating seeds and mature plants. In Epipactis atrorubens, the fungi detected were similar at all three life stages, but different fungal lineages produced a difference in seedling germination performance. Our results demonstrate that there can be a narrow checkpoint for mycorrhizal range during seedling growth relative to the more promiscuous germination and mature stages of these plants' life cycle.

  16. [Grain filling dynamics and germination characteristics of Bupleurum chinense seeds].

    Science.gov (United States)

    Jin, Xin; Ren, Bing; Cao, Ai-Nong; Jin, Xiao-Jun

    2014-10-01

    Bupleurum chinense used in the study were cultivated in the experimental fields of Gansu agricultural University for three years. The seeds of B. chinense were collected every 3 days 10 d after the blossom. The result showed that the 1 000-grain fresh weight reached the maximum 43 d after the blossom and then decreased rapidly, at the mature period the fresh weight of seeds were falling to the same level of the dry weight. The dynamic change of the grain dry matter accumulation showed as an S-shape curve, the rapid increase stage was 25-34 d following the flower, and the grain filling was ended 46 d after blossom. Grain filling rate was under the law "fast-slow-fast-slow". And there were two peaks of grain filling rate appeared, after reached the second peak 28 d after the flower the filling rate decreased rapidly and stayed steadily 43 d after flowering. The dehydration rate was also measured at its maximum 43 d following flower. The indexes of seeds all reached the top 52 days following the blossom, when the germination rate reached the peak (34.33%) and water content of seeds was near 10%. The rate of germination and the 1 000-graid weight of seed showed significant positive correlation, while the water content of seeds was found significant negatively correlation with germination percentage. So the best time for harvest should be 52 d after flowering (9 month), the seeds collected at that time showed both high quality and germination rate.

  17. TLR7 influences germinal center selection in murine SLE.

    Science.gov (United States)

    Boneparth, Alexis; Huang, Weiqing; Bethunaickan, Ramalingam; Woods, Megan; Sahu, Ranjit; Arora, Shitij; Akerman, Meredith; Lesser, Martin; Davidson, Anne

    2015-01-01

    TLR7 enhances germinal center maturation and migration of B cells to the dark zone where proliferation and somatic hypermutation occur. Our goal was to determine how Tlr7 dose influences selection of the autoreactive B cell repertoire in NZW/BXSB. Yaa mice bearing the site-directed heavy chain transgene 3H9 that encodes for the TLR7 regulated anti-CL response. To create a physiologic setting in which autoreactive B cells compete for survival with non-autoreactive B cells, we generated bone marrow chimeras in which disease onset occurred with similar kinetics and the transferred 3H9+ female non-Yaa, male Yaa or male TLR7(-/Yaa) cells could be easily identified by positivity for GFP. Deletion of 3H9 B cells occurred in the bone marrow and the remaining 3H9 follicular B cells manifested a decrease in surface IgM. Although there were differences in the naïve repertoire between the chimeras it was not possible to distinguish a clear pattern of selection against lupus related autoreactivity in TLR7(-/Yaa) or female chimeras. By contrast, preferential expansion of 3H9+ B cells occurred in the germinal centers of male Yaa chimeras. In addition, although all chimeras preferentially selected 3H9/Vκ5 encoded B cells into the germinal center and plasma cell compartments, 3H9 male Yaa chimeras had a more diverse repertoire and positively selected the 3H9/Vκ5-48/Jκ4 pair that confers high affinity anti-cardiolipin activity. We were unable to demonstrate a consistent effect of Tlr7 dose or Yaa on somatic mutations. Our data show that TLR7 excess influences the selection, expansion and diversification of B cells in the germinal center, independent of other genes in the Yaa locus.

  18. Dynamics of phosphorus compounds in ripening and germinating cereal grains. Part II. Changes in phosphorus compounds content during germination of wheat, barley and rye grains

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    J. Tłuczkiewicz

    2015-01-01

    Full Text Available The dynamics of phosphorus compounds was investigated in the embryos and endosperm of wheat (Grana, barley (Kosmos and rye (Pancerne grain after 2, 4 and 6 days of germination. In germinating grain the phosphorus compounds transformations ran along the way of synthesis in the embryo and of breakdown in the endosperm. The level of phosphorus: inorganic, nucleotides, saccharides esters and their metabolites, lipid, RNA, DNA, phytin free and phytin bound with proteins and proteins rapidly increased in germinating seed embryos. The content of phosphorus free phytin and that bound with proteins, lipids, RNA and DNA in the endosperm rapidly decreased during germination. On the other hand, the saccharides phosphorus and that of their metabolites did not change, and inorganic, nuclotides and proteins-P slightly increased. Germinating rye grains showed a higher rate of synthesis in the embryos and of breakdown in the endosperm of the investigated phosphorus compounds than wheat and barley grains.

  19. Ultrastructure and germination of Vitis vinifera cv. Loureiro pollen.

    Science.gov (United States)

    Abreu, I; Costa, I; Oliveira, M; Cunha, M; de Castro, R

    2006-08-01

    The cultivar Loureiro of Vitis vinifera is one of the most economically important, recommended in almost the totality of the Região Demarcada dos Vinhos Verdes. In vineyards, the grape productivity of this cultivar is normal while in others it is extremely low. The aim of this work was to study the morphology and germination of Vitis vinifera cv. Loureiro pollen with high and low productivity. The pollen grain was examined under light, transmission and scanning electron microscopy. Typically V. vinifera pollen present three furrows but in the cultivar Loureiro we found tricolporated and acolporated (without furrows or pores) pollen grains. Both pollen types present generative and vegetative cells with the usual aspect and a dense cytoplasm rich in organelles. In the acolporated pollen a continuous exine layer and an irregular intine layer were observed. Differences were found in the starch accumulation, since only in tricolporated pollen abundant plastids filled with numerous starch granules were observed. To determine the causes of the low productivity of this cultivar we tested pollen viability by the fluorochromatic reaction and pollen germinability by in vitro assays. We observed that the acolporated pollen grain is viable, but no germination was recorded.

  20. Glyphosate Can Decrease Germination of Glyphosate-Resistant Soybeans.

    Science.gov (United States)

    Gomes, Marcelo Pedrosa; Bicalho, Elisa Monteze; Smedbol, Élise; Cruz, Fernanda Vieira da Silva; Lucotte, Marc; Garcia, Queila Souza

    2017-03-22

    We investigated the effects of different concentrations of glyphosate acid and one of its formulations (Roundup) on seed germination of two glyphosate-resistant (GR) and one non-GR variety of soybean. As expected, the herbicide affected the shikimate pathway in non-GR seeds but not in GR seeds. We observed that glyphosate can disturb the mitochondrial electron transport chain, leading to H2O2 accumulation in soybean seeds, which was, in turn, related to lower seed germination. In addition, GR seeds showed increased activity of antioxidant systems when compared to non-GR seeds, making them less vulnerable to oxidative stress induced by glyphosate. The differences in the responses of GR varieties to glyphosate exposure corresponded to their differences in enzymatic activity related to H2O2 scavenging and mitochondrial complex III (the proposed site of ROS induction by glyphosate). Our results showed that glyphosate ought to be used carefully as a pre-emergence herbicide in soybean field crop systems because this practice may reduce seed germination.

  1. EFFECT OF HEAT TREATMENT ON THE GERMINATION OF SEEDS SOEL

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    Y. M’Sadak

    2015-01-01

    Full Text Available The object of this work was to study the effect of thermal treatments (in the oven and in the compost on the seed germination SOEL. The laboratory evaluation on the treatment in the oven berries at two temperatures (50°C and 60°C for three exposure time ( one day, two days and three days gave a germination rate zero for 60°C for an exposure time of one day. The spatio-temporal thermal monitoring of forestry compost windrow which was introduced to deal with berries SOEL showed a substantially homogeneous distribution of the temperature rising to 60°C and even longer swath stretching and used for a time period of 5 consecutive days. The germination rate was zero for all fruit seeds treated before the first reversal fact, regardless of the depth and location of the windrow considered that the berries were introduced. Thus, composting can be a solution to prevent the spread of SOEL by seed.

  2. Muricholic acids inhibit Clostridium difficile spore germination and growth.

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    Michael B Francis

    Full Text Available Infections caused by Clostridium difficile have increased steadily over the past several years. While studies on C. difficile virulence and physiology have been hindered, in the past, by lack of genetic approaches and suitable animal models, newly developed technologies and animal models allow these processes to be studied in detail. One such advance is the generation of a mouse-model of C. difficile infection. The development of this system is a major step forward in analyzing the genetic requirements for colonization and infection. While important, it is equally as important in understanding what differences exist between mice and humans. One of these differences is the natural bile acid composition. Bile acid-mediated spore germination is an important step in C. difficile colonization. Mice produce several different bile acids that are not found in humans. These muricholic acids have the potential to impact C. difficile spore germination. Here we find that the three muricholic acids (α-muricholic acid, β-muricholic acid and ω-muricholic acid inhibit C. difficile spore germination and can impact the growth of vegetative cells. These results highlight an important difference between humans and mice and may have an impact on C. difficile virulence in the mouse-model of C. difficile infection.

  3. Effect of endosperm mutants on maize seed germination

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    Pajić Zorica

    2004-01-01

    Full Text Available The expression of genetic potential of yielding and quality of a certain genotype depends among other factors on seed quality. Seed is very important not only for the reproduction of the particular plant species, but also, for the contemporary plant production. Each part of maize seed (pericarp endosperm and germ has a specific function in the complex process of germination and emergence. The following three genotypes of different endosperm types were observed: ZPSC 42A (standard grain quality dent hybrid ZPSC 504 su (sweet maize hybrid with a sugary gene and ZPSyn.II sh2 (synthetic population with a shranken2 gene. Seed viability of the stated genotypes was determined by the accepted ISTA methods: standard method accelerating age and cold test. Obtained results point out to differences in the germination capacity of the observed genotypes. The greatest reduction of the germination capacity and the emergence rate was expressed by the application of the accelerating ageing method. Appeared differences are probably a result of the endosperm texture (type, grain weight, sugar content and pericarp thickens and composition.

  4. [Galactomannan breakdown in germinating carob seeds (Ceratonia siliqua L.)].

    Science.gov (United States)

    Seiler, A

    1977-01-01

    In the first days of germination of carob seeds (Ceratonia siliqua L., Leguminosae) (until penetration of the seed coat by the radicle) oligosaccharides of the raffinose series present in the endosperm and embryo are hydrolysed. The mobilisation of the reserve galactomannan of the endosperm begins after the emergence of the radicle. Its degradation is effected by hydrolytic enzymes (α-galactosidase [EC 3.2.1.22], β-mannanase, [EC 3.2.1.25] and β-mannosidase [EC 3.2.1.25]) and the breakdown products-galactose and mannose-are continuously metabolised by the embryo. At the same time starch synthesis is observed in the embryo.In the germination of Ceratonia siliqua seeds the embryo does not have a direct effect on the mobilisation of the reserve polysaccharide as it does in the case of barley. The endosperm consists of living cells which, independently of the embryo, synthesise the enzymes used for galactomannan breakdown. A weak α-galactosidase activity is already present in the endosperm of mature dry seeds. This activity cannot be suppressed by inhibitors of transcription or translation, so that their presence does not prevent degradation of oligosaccharides of the raffinose series.A high proportion of the α-galactosidase responsible for the breakdown of the galactomannan is synthesised de novo during germination. Such synthesis could be demonstrated by the incorporation of [U-(14)C]serine and could be inhibited by actinomycin D or cycloheximide.

  5. From minisatellites and genes: When do germinal mutations occur

    Energy Technology Data Exchange (ETDEWEB)

    Mohrenweiser, H. [Lawrence Livermore National Lab., CA (United States)

    1997-10-01

    Utilization of molecular techniques has provided insight into the molecular techniques has provided insight into the molecular techniques has provided insight into the molecular character and origins of spontaneous and induced germinal mutations. Review of the variants and disease loci suggests differences among loci in the frequency of nucleotide substitutions and more complex events. Mechanistic features associated with the alterations in DNA structure are observed in each variant class. The spectrum of mutations identified reflects the gene structure and the selective pressure generating disease phenotypes, and the techniques employed to screen for variation. Locus specificity in spectra has the potential to compromise estimates of increases in germinal gene mutation rates. Recent studies have identified mosaicism, rather than de novo mutation, as the explanation for the non-traditional pattern of inheritance of disease in some families. Mosaicism is a concern for studies of induced mutation rates as it reflects embryonic exposure of the parent of the proband. This is in contrast to the {open_quotes}normal expectation{close_quotes} that induced mutations result from parental exposure to genotoxins in the environment. Observations suggest that the germ cell stage sensitivity may reflect interaction of the mutagen and the loci screened. The mosaicism and germ cell stage issues, in conjunction with incomplete ascertainment of mutational events, increase the complexity of efforts to estimate induced germinal mutation rates and associated health consequences in populations exposed to genotoxic agents.

  6. Fruit biometry and seed germination of Syagrus romanzoffiana (Cham. Glassm

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    Flora Goudel

    2013-03-01

    Full Text Available Syagrus romanzoffiana (Cham. Glassm. is a species native to Brazil that is of ecological and aesthetic importance. This study aims to describe the biometric characteristics of S. romanzoffiana fruits and to assess the effects that treatments meant to overcome dormancy and partial drying have on seed germination. For biometric characterization, each repetition consisted of 50 fruits from eight clusters (total, 400 fruits. To evaluate methods for overcoming dormancy, seeds representative of populations were treated by perforation of the operculum; perforation of the operculum and immersion in water for 24 hours; cracking; exposure to fire for three minutes; and non-removal of fibers. There was also a control group. In a second experiment, seeds were partially dried. We determined the proportional moisture content of newly harvested seeds (20.2% and dried them down to moisture contents of 15.5% and 12.7%. All seeds were subjected to a germination test at 30ºC. The fruits showed biometric variations, with an average of 21.7 mm in longitudinal diameter and 19.7 mm in polar diameter, and a fresh mass of 5.61 g, of which 59.29% was pulp. The highest germination rates and vigor to overcome dormancy occurred after the operculum was perforated and the seeds were soaked in water for 24 hours. The results of the partial drying treatments did not differ sufficiently to discourage dormancy in any significant manner.

  7. Methods to promote germination of dormant Setaria viridis seeds.

    Science.gov (United States)

    Sebastian, Jose; Wong, Mandy Ka; Tang, Evan; Dinneny, José R

    2014-01-01

    Setaria viridis has recently emerged as a promising genetic model system to study diverse aspects of monocot biology. While the post-germination life cycle of S. viridis is approximately 8 weeks long, the prolonged dormancy of freshly harvested seeds can more than double the total time required between successive generations. Here we describe methods that promote seed germination in S. viridis. Our results demonstrate that treating S. viridis seeds with liquid smoke or a GA3 and KNO3 solution improves germination rates to 90% or higher even in seeds that are 6 days post-harvest with similar results obtained whether seeds are planted in soil or on gel-based media. Importantly, we show that these treatments have no significant effect on the growth of the adult plant. We have tested these treatments on diverse S. viridis accessions and show variation in their response. The methods described here will help advance research using this model grass species by increasing the pace at which successive generations of plants can be analyzed.

  8. Methods to promote germination of dormant Setaria viridis seeds.

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    Jose Sebastian

    Full Text Available Setaria viridis has recently emerged as a promising genetic model system to study diverse aspects of monocot biology. While the post-germination life cycle of S. viridis is approximately 8 weeks long, the prolonged dormancy of freshly harvested seeds can more than double the total time required between successive generations. Here we describe methods that promote seed germination in S. viridis. Our results demonstrate that treating S. viridis seeds with liquid smoke or a GA3 and KNO3 solution improves germination rates to 90% or higher even in seeds that are 6 days post-harvest with similar results obtained whether seeds are planted in soil or on gel-based media. Importantly, we show that these treatments have no significant effect on the growth of the adult plant. We have tested these treatments on diverse S. viridis accessions and show variation in their response. The methods described here will help advance research using this model grass species by increasing the pace at which successive generations of plants can be analyzed.

  9. FcgammaRIIb expression on human germinal center B lymphocytes.

    Science.gov (United States)

    Macardle, Peter J; Mardell, Carolyn; Bailey, Sheree; Wheatland, Loretta; Ho, Alice; Jessup, Claire; Roberton, Donal M; Zola, Heddy

    2002-12-01

    IgG antibody can specifically suppress the antibody response to antigen. This has been explained by the hypothesis that signaling through the B cell antigen receptor is negatively modulated by the co-ligation of immunoglobulin with the receptor for IgG, FcgammaRIIb. We hypothesized that inhibitory signaling through FcgammaRIIb would be counter-productive in germinal center cells undergoing selection by affinity maturation, since these cells are thought to receive a survival/proliferative signal by interacting with antigen displayed on follicular dendritic cells. We have identified and characterized a population of B lymphocytes with low/negative FcgammaRIIb expression that are present in human tonsil. Phenotypically these cells correspond to germinal center B cells and comprise both centroblast and centrocyte populations. In examining expression at the molecular level we determined that these B cells do not express detectable mRNA for FcgammaRIIb. We examined several culture conditions to induce expression of FcgammaRIIb on germinal center cells but could not determine conditions that altered expression. We then examined the functional consequence of cross-linking membrane immunoglobulin and the receptor for IgG on human B lymphocytes. Our results cast some doubt on the value of anti-IgG as a model for antigen-antibody complexes in studying human B cell regulation.

  10. Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

    Energy Technology Data Exchange (ETDEWEB)

    Lin Daohui [Department of Environmental Science, Zhejiang University, Hangzhou 310028 (China); Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States); Xing Baoshan [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States)], E-mail: bx@pssci.umass.edu

    2007-11-15

    Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC{sub 50}) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth.

  11. A Quick-Test for Biochar Effects on Seed Germination ...

    Science.gov (United States)

    Biochar is being globally evaluated as a soil amendment to improve soil characteristics (e.g. soil water holding, nutrient exchange, microbiology, pesticides and chemical availability) to increase crop yields. Unfortunately, there are no quick tests to determine what biochar types are most effective at improving soil characteristics amenable for higher crop yields. Seed germination is a critical parameter for plant establishment and may be a quick indicator of biochar quality. We adapted Oregon State University Seed Laboratory procedures to develop a “quick-test” for screening the effects of biochar on seed germination. We used 11.0 cm rectangular x 3.5 cm deep containers fitted with blotter paper. The paper was premoistened with reverse-osmosis water, followed by placement of seeds (25 in a uniform 5 x 5 vacuum-assisted pattern, and biochar mixtures). A Norfolk and Coxville soil series from South Carolina were used. A total of 18 biochars were evaluated that were produced from 6 feedstocks (pine chips, poultry litter, swine solids, switchgrass, and two blends of pine chips and poultry litter); with biochar from each feedstock made by pyrolysis at 350, 500 and 700 ̊ C. Crops were cabbage, cucumber, onion, ryegrass and tomato. Preliminary results from the test indicated differences in seed germination due to soil type and possibly soil x biochar feedstock interactions. Other measurements including shoot dry weight per plate and pH of the soil+ biochar mixtur

  12. Seed Germination and Seedling Survival of Spartina alterniflora Loisel

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    Patrick D. Biber

    2008-01-01

    Full Text Available Spartina alterniflora (smooth cordgrass is a widespread intertidal salt marsh plant that is frequently used in coastal restoration projects. Seeds collected in 2004 were tested for seed germination and seedling survival after 6 months of cold seed storage to determine differences among collection locations (experiment 1. Seeds collected in 2005, after Hurricane Katrina, were tested for seed germination and seedling survival from 0 to 15 months of cold seed storage time to determine minimum and maximum storage time and seedling survival rates (experiment 2. Seed germination increased from 1-4 months of cold, wet storage (stratification and then began to decline. Survival of the seedlings was highest after 2 months of stratification. In experiment 1, seedling size was found to vary widely among seedlings of the same source and age. Seedling height at 22 days after planting ranged from 2-16 cm, despite identical environmental conditions. Selective breeding could target plants with fast early growth characteristics to promote strains that can be raised quickly in a nursery in response to demands for restoration.

  13. QTL Mapping of Low Temperature on Germination rate of Rice

    Institute of Scientific and Technical Information of China (English)

    CHEN Liang; LOU Qiao-jun; SUN Zong-xiu; XING Yong-zhong; YU Xin-qiao; LUO Li-jun

    2006-01-01

    To investigate the low temperature on germination capacity (LTG) a double haploid rice (DH) population with 198 lines derived from anther culture of F1 hybrid with indica line Zhenshan 97B and a perennial japonica line AAV002863 was used to construct a linkage map with 140 SSR markers. The germination rate in Zhenshan 97B and AAV002863 was 79.7% and 30.1%, while in DH population it ranged from 0 to 100% at 15℃ after 6 days. Quantitative trait loci (QTLs) controlling low temperature germinability were identified on chromosomes 3 and 10. The percentage of observed phenotypic variance attributed to qLTG-3 and qLTG-10 was 12.6% and 12.9%, respectively. Allele from Zhenshan 97B increased the LTG at qLTG-3 region, while allele from AAV002863 increased the LTG at qLTG-10 region. One pair of epistatic interaction was detected between loci on chromosomes 3 and 10. The main-effect of QTL on chromosome 10 was also involved in epistatic interaction.

  14. Germination and initial development of aroeira (Myracrodruon urundeuva seedlings

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    Silvana de Paula Quintão Scalon

    2012-12-01

    Full Text Available Aroeira has great economic importance due to its wood useful, tannins extraction and use in the pharmacology. The aim of this work was to evaluate the germination aspects and initial seedlings development of aroeira, under gibberellins, substrata and shading effects, and for that two experiments were led out. In the first one, seeds were previously soaked for 24 hours in water and in 100 mg.L-1 gibberellin solution and were sowed directly in cells trays in the following substrata: land and sand (1:1 and 1:2 and Plantmax . In the second experiment, 15 cm length seedlings were transplanted to polyethylene sacks filled out land+sand+poultry manure (1:1:1 partly decomposed and they were maintained at greenhouse for 15 days. Soon after, seedlings were transferred for the following conditions: shading (50% and full sun and they were 50 mg.L-1 and 150 mg.L-1 gibberellins solutions pulverized, as control seedlings water pulverized. Aroeira seeds should not be previously water or gibberellins imbibed before being sowed. The best substrata for aroeira seeds germination was Plantmax without germinative treatments to reach higher than 80% of seedlings survival. The seedlings developed better at full sun light and the gibberellin. It was observed increment in height, diameter, foliar area and fresh and dry mass from aerial and root part when compared to shading situation. The gibberellins applications did not influence the aroeira seedlings initial growth characteristics.

  15. Effect of seed treatment for laboratory germination of Albizia chinensis

    Institute of Scientific and Technical Information of China (English)

    A. Nongrum; L. Kharlukhi

    2013-01-01

    Seeds of Albizia chinensis(Osb.) Merr. in addition to water were also treated with different treatments by incubating in ethyl alcohol, acetone, and petroleum ether at room temperature for different durations. Seed heat treatment was done at temperatures of 30, 40 and 60ºC for different durations up to 24 h. To overcome dormancy caused by the impermeable seed coat, seeds were nicked and also treated with concen-trated sulphuric acid for different durations. Seeds responded to treat-ments with sulphuric acid and nicking only. Treatment with sulphuric acid for 20 and 30 min showed maximum germination at all incubation temperatures as compared to untreated controls and seeds treated with sulphuric acid for 10 min and nicking. Seedling length was greatest from seeds treated with sulphuric acid for 20 and 30 min and incubated at 30 ºC. Seedling dry weight was highest from nicked seeds incubated at 20ºC. The most favourable incubation temperature was 30 ºC as evidenced from GRI (germination rate index) and GV (germination value). After ascertaining the seed response and performance we recommend that seeds of Albizia chinensis be treated with sulphuric acid for 20 or 30 min and incubation temperature of 25 to 30ºC.

  16. Germinated grains: a superior whole grain functional food?

    Science.gov (United States)

    Nelson, Kristina; Stojanovska, Lily; Vasiljevic, Todor; Mathai, Michael

    2013-06-01

    Grains are global dietary staples that when consumed in whole grain form, offer considerable health benefits compared with milled grain foods, including reduced body weight gain and reduced cardiovascular and diabetes risks. Dietary patterns, functional foods, and other lifestyle factors play a fundamental role in the development and management of epidemic lifestyle diseases that share risks of developing adverse metabolic outcomes, including hyperglycaemia, hypertension, dyslipidaemia, oxidative stress, and inflammation. Whole grains provide energy, nutrients, fibres, and bioactive compounds that may synergistically contribute to their protective effects. Despite their benefits, the intake of grains appears to be lower than recommended in many countries. Of emerging interest is the application of germination processes, which may significantly enhance the nutritional and bioactive content of grains, as well as improve palatability. Enhancing grain foods in a natural way using germination techniques may therefore offer a practical, natural, dietary intervention to increase the health benefits and acceptability of whole grains, with potentially widespread effects across populations in attenuating adverse lifestyle disease outcomes. Continuing to build on the growing body of in-vitro studies requires substantiation with extended in-vivo trials so that we may further develop our understanding of the potential of germinated grains as a functional food.

  17. RopGEF2 is involved in ABA-suppression of seed germination and post-germination growth of Arabidopsis.

    Science.gov (United States)

    Zhao, Shujuan; Wu, Yuxuan; He, Yuqing; Wang, Yarui; Xiao, Jun; Li, Lin; Wang, Yanping; Chen, Xi; Xiong, Wei; Wu, Yan

    2015-12-01

    The involvement of Rho of Plants (ROP) GTPases in abscisic acid (ABA) signalling in Arabidopsis has been demonstrated in many studies. However, the roles of RopGEFs (Rop guanine nucleotide exchange factors), which modulate ROP activities in ABA signalling, are poorly understood. Here, we demonstrate that RopGEF2 may play a negative role in ABA-suppressed seed germination and post-germination growth. We show that disruption of RopGEF2 enhances sensitivity to exogenous ABA in seed germination assays and that RopGEF2pro-GUS is mainly expressed in developing embryos and germinating seeds. Interestingly, YFP-RopGEF2 is located in both the cytoplasmic region and in mitochondria. Notably, the PRONE2 (plant-specific ROP nucleotide exchanger 2) domain of RopGEF2 is detected in mitochondria, whereas the N-terminus of RopGEF2 is shown to be in the cytosol. After ABA treatment, degradation of RopGEF2 is triggered in the cytosol through the ubiquitin-26S proteasome system. The binding of RopGEF2 to ROP2, ROP6 or ROP10, which has been demonstrated to be involved in ABA signalling, not only alters the localization of RopGEF2 but also enables RopGEF2 to escape degradation in the cell. Thus, in this study, we deduce a sophisticated mechanism of ABA-mediated RopGEF2-ROP signalling, which potentially implicates the inactivation of ROPs in responsiveness to ABA. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  18. Proteomic analysis of seed germination under salt stress in soybeans

    Institute of Scientific and Technical Information of China (English)

    Xiao-yan XU; Rui FAN; Rui ZHENG; Chun-mei LI; De-yue YU

    2011-01-01

    Soybean (Glycine max (L.) Merrill) is a salt-sensitive crop,and its production is severely affected by saline soils.Therefore,the response of soybean seeds to salt stress during germination was investigated at both physiological and proteomic levels.The salt-tolerant cultivar Lee68 and salt-sensitive cultivar N2899 were exposed to 100 mmol/L NaCl until radicle protrusion from the seed coat.In both cultivars,the final germination percentage was not affected by salt,but the mean germination times of Lee68 and N2899 were delayed by 0.3 and 1.0 d,respectively,compared with controls.In response to salt stress,the abscisic acid content increased,and gibberellic acid (GA1+3) and isopentenyladenosine decreased.Indole-3-acetic acid increased in Lee68,but remained unchanged in N2899.The proteins extracted from germinated seeds were separated using two-dimensional gel electrophoresis (2-DE),followed by Coomassie brilliant blue G-250 staining.About 350 protein spots from 2-DE gels of pH range 3 to 10 and 650 spots from gels of pH range 4 to 7 were reproducibly resolved,of which 18 protein spots showed changes in abundance as a result of salt stress in both cultivars.After matrix-assisted laser desorption ionization-time of flight-mass spectroscopy (MALDI-TOF-MS) analysis of the differentially expressed proteins,the peptide mass fingerprint was searched against the soybean UniGene database and nine proteins were successfully identified.Ferritin and 20S proteasome subunit β-6 were up-regulated in both cultivars.Glyceraldehyde 3-phosphate dehydrogenase,glutathione S-transferase (GST) 9,GST 10,and seed maturation protein PM36 were down-regulated in Lee68 by salt,but still remained at a certain level.However,these proteins were present in lower levels in control N2899 and were up-regulated under salt stress.The results indicate that these proteins might have important roles in defense mechanisms against salt stress during soybean seed germination.

  19. Phyotoxicity of diesel soil contamination on the germination of Lactuca sativa and Ipomoea batatas.

    Science.gov (United States)

    Fatokun, Kayode; Lewu, Francis Bayo; Zharare, Godfrey Elijah

    2015-11-01

    Phytotoxic effect of diesel contaminated soil on germination rate of Lactuca sativa and Ipomoea batatas, at two concentrations ranges (0-6ml and 0-30ml), were investigated and compared. Diesel soil contamination was simulated and soil samples were taken from contaminated soil at 1, 5,10, 15, 25, 50, 75 and 100 days should be after planting. The result showed that in both plant species, diesel inhibited germination in a concentration dependent manner, Also, the influence of diesel contamination diminished with increased time duration; suggesting possible reduction in diesel toxicity over time. However, germination of lettuce was significant and negatively correlated (r2 = -0.941) with diesel contamination as compared to sweet potato (r2 = -0.638).Critical concentration of diesel in relation to seed germination of L. sativa was lower than vegetative germination of I. batatas, indicating that germination of I. batatas was less sensitive to diesel contamination as compared to L. sativa.

  20. Influence de quelques facteurs environnementaux sur la germination d'Euphorbia heterophylla L. (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    Ipou Ipou, J.

    2004-01-01

    Full Text Available Influence of some Environmental Factors on Euphorbia heterophylla L. (Euphorbiaceae Seeds Germination. In Ivory Coast, Euphorbia heterophylla appears as a weed in cotton fields. Effects of temperature, light and burying levels on its seed germination were tested. Temperature effects were monitored by means of 4 procedures, using a range of temperatures between 20 and 35 °C. The germination latency period can vary between 1 and 2 days, according to the temperature. After 4 days, germination rates were not longer related to temperature and were very similar. Germination can not happen without light. In order to measure the effect of burying levels, six series of 100 seeds were buried; the first at ground level, the others respectively 2, 4, 6, 8 and 9 cm deeper. Optimal germination rates were found for seeds that were buried between 0 and 6 cm.

  1. Food Quality Improvement of Soy Milk Made from Short-Time Germinated Soybeans

    Directory of Open Access Journals (Sweden)

    Susu Jiang

    2013-05-01

    Full Text Available The objectives of this study were to develop soy milk with improved food quality and to enhance the functional attributes by incorporating short-time germination into the processing. Changes in trypsin inhibitor activity (TIA, phytic acid content and total phenolic content (TPC in soy milk produced from soybeans germinated within 72 h were investigated to determine the optimum germination condition. Results from the present research showed significant (p < 0.05 improvement of TPC in cooked germinated soybean milk, while both the TIA and phytic acid content were decreased significantly (p < 0.05. In the subsequent evaluation on the quality attributes under the optimum germination condition, soy milk made from 28 h-germinated soybeans presented enhanced nutritional value and comparable physicochemical properties to conventional soy milk. The current approach provides a feasible and convenient way for soy-based product innovation in both household and industrial settings.

  2. Effects of stress temperatures of germination on polyamine titers of soybean seeds

    Science.gov (United States)

    Pineda-Mejia, Renan

    High and low stress temperatures during seed germination and seedling development limit total germination and the rate of germination and growth. Changes in polyamine (PA) concentrations in seeds of different species have been associated with germination, growth and environmental stresses such as temperature, drought, oxygen, chilling injury and osmotic conditions. Two studies were conducted to determine the effect of stress temperatures during germination and seedling development on polyamine titers in soybean seeds. Three germination temperatures, 25, 30, and 36°C were used in the first study to evaluate their influence on changes in polyamine concentrations in soybean seeds germinated at 76 and 90 hours. The polyamines (PAs), cadaverine (Cad), putrescine (Put), spermidine (Spd), agmatine (Agm), and spermine (Spin) were quantified by HPLC using a cation exchange column and an electrochemical detector. Cad, Put, Agm, and Spd declined as the germination temperatures increased from 25 to 36°C. Conversely, Spin increased considerably with an increase in temperature. Total germination was reduced from 97.2 to 92.5% as germination temperatures increased from 25 to 36°C. Germination time did not affect Cad, Agm and Spm, and total germination, however, the interaction between temperature and germination time for Put and Spd concentrations was significant. In the second study, changes in PA concentrations, seedling growth, germination time (t50), fresh and dry weight, and moisture content were measured in the embryonic axis and cotyledons of soybean seeds germinated at 10 and 25°C through six stages of germination dry seed (DS), testa split (TS), radicle at 10 mm (Ra-10), root hairs visible (RHV), secondary root primordia (SRP), and complete seedling (CS). The concentrations of Cad and Put in the embryonic axis, were significantly higher in seeds germinated under low temperature than in seeds at 25°C (approximately 10 and 3 fold respectively). However, this

  3. Influence of germination time of brown rice in relation to flour and gluten free bread quality.

    Science.gov (United States)

    Cornejo, Fabiola; Rosell, Cristina M

    2015-10-01

    The effect of germination time on physicochemical characteristics of brown rice flour and its effect on gluten free bread qualities have been investigated. Germination was carried out at 28 °C and 100 % RH for 12, 24 and 48 h; brown rice and soaked brown rice was also analyzed. Significant changes on hydration and pasting properties of brown rice flour were found during germination. The starch degradation by enzyme activity could be evidenced with the decrease in viscosity and water binding capacity (WBC). No significant effect in specific volume, humidity and water activity of the gluten free bread was found as germination time increase, but a significant softness of the crumb was obtained. However, at 48 h of germination, the intense action of α amylase could result in excessive liquefaction and dextrinisation, causing inferior bread quality. Overall, germinated rice flour showed appropriate functionality for being used as raw ingredient in gluten free breadmaking.

  4. DIFFERENT SUBSTRATA EFFECTS IN THE GERMINATION OF Ochroma pyramidale (CAV. EX LAM. URB. (BOMBACACEAE

    Directory of Open Access Journals (Sweden)

    Fabrízia de Oliveira Alvino

    2010-08-01

    Full Text Available The objective of this paper was to analyze the effect of different substrata in the germination of Ochroma pyramidale (Cav. ex Lam. Urb. (Bombacaceae. The experiment was conducted in delineation randomized with three treatments (substratum and four repetitions of 25 seeds. The following substrata had been tested: sand + vermiculite (1:1; vermiculite and, sand + shavings (1:1. The effect of substrata through the percentage of germination of the seeds, average time of germination and index of germination speed (IGS were evaluated. There had been significant difference between the treatments in of all the observed variable. The seeds, when conditioned in vermiculite, had presented the biggest tax of germination, greatest speed and lowest germination time.

  5. Loss of interleukin-21 leads to atrophic germinal centers in multicentric Castleman's disease.

    Science.gov (United States)

    Yajima, Hidetaka; Yamamoto, Motohisa; Shimizu, Yui; Sakurai, Nodoka; Suzuki, Chisako; Naishiro, Yasuyoshi; Imai, Kohzoh; Shinomura, Yasuhisa; Takahashi, Hiroki

    2016-01-01

    Both multicentric Castleman's disease (MCD) and immunoglobulin (Ig)G4-related disease (IgG4-RD) are systemic diseases, presenting with hypergammaglobulinemia and elevated serum levels of IgG4. However, with regard to histopathological findings, MCD shows atrophic germinal centers. On the other hand, expanded germinal centers are detected in IgG4-RD. We extracted germinal centers from specimens of each disorder by microdissection and analyzed the expression of mRNAs by real-time polymerase chain reaction to clarify the mechanisms underlying atrophied germinal centers in MCD. This analysis disclosed loss of interleukin (IL)-21 and B cell lymphoma (Bcl)-6 in the germinal centers of MCD. Loss of IL-21 is considered to be involved in the disappearance of Bcl-6 and leads to atrophied germinal centers in MCD.

  6. Critical role of SHP2 (PTPN11) signaling in germinal center-derived lymphoma.

    Science.gov (United States)

    Jiang, Xin; Guo, Honggang; Wu, Jianguo; He, Qiang; Li, Yiqiao; Wang, Miao; Pan, Hongyang; Li, Wande; Wang, Jinjie; Wang, Qingqing; Shen, Jing; Ke, Yuehai; Zhou, Ren

    2014-12-01

    Germinal center lymphoma is a heterogeneous human lymphoma entity. Here we report that constitutive activity of SHP2 (PTPN11) and its downstream kinase ERK is essential for the viability of germinal center lymphoma cells and disease progression. Mechanistically, SHP2/ERK inhibition impedes c-Myc transcriptional activity, which results in the repression of proliferative phenotype signatures of germinal center lymphoma. Furthermore, SHP2/ERK signaling is required to maintain the CD19/c-Myc loop, which preferentially promotes survival of a distinct subtype of germinal center lymphoma cells carrying the MYC/IGH translocation. These findings demonstrate a critical function for SHP2/ERK signaling upstream of c-Myc in germinal center lymphoma cells and provide a rationale for targeting SHP2 in the therapy of germinal center lymphoma.

  7. Allelopathy of the invasive plant Bidens frondosa on the seed germination of Geum japonicum var. chinense.

    Science.gov (United States)

    Wang, X F; Hassani, D; Cheng, Z W; Wang, C Y; Wu, J

    2014-12-12

    Five gradient concentrations (0.02, 0.04, 0.06, 0.08, and 0.10 g/mL) of leaching liquors from the roots, stems, and leaves of the invasive plant Bidens frondosa were used as conditioning fluid to examine its influence on seed germination conditions of the native plant Geum japonicum var. chinense in Huangshan. All leaching liquors of organs suppressed the seed germination of Geum japonicum var. chinense and reduced the final germination percentage and rate, and increased the germination inhibition rate, with a bimodal dependence on concentration. The leaching liquor inhibited the seed germination significantly at the concentration of 0.02 g/mL respectively. The seed germination was also inhibited as the concentration reached to 0.04 g/mL and beyond. Hence the allelopathic effects of the organs were significantly enhanced respectively. This phenomenon represented the presence of allelopathy substances in the root, stem and leaf of Bidens frondosa.

  8. Actions of gibberellic Acid and phytochrome on the germination of grand rapids lettuce seeds.

    Science.gov (United States)

    Vidaver, W; Hsiao, A I

    1974-02-01

    Red light and gibberellic acid were about equally effective in promoting germination of Grand Rapids lettuce (Lactuca sativa L.) seeds. With initial far red light treatment more than 80% remained dormant in subsequent dark storage. After 2 days of dark storage, red light effectively promoted germination, while gibberellic acid action was weak. With between 2 and 10 days of dark storage, gibberellic acid had little effect, while promotion by red light decreased slowly and finally disappeared. After 10 days of dark storage, both gibberellic acid and red light were required for germination. The dark storage treatment interferes with phytochrome-independent germination processes and cannot be overcome by added gibberellic acid. However, storage may also decrease the effectiveness of endogenous gibberellins. Phytochrome-dependent germination seems to require only low levels of endogenous gibberellin activity or the addition of gibberellic acid. Gibberellins and red light appear to act on germination by regulation of sequential sites of a branched-looped pathway.

  9. Enzymatic characterization of germination-specific cysteine protease-1 expressed transiently in cotyledons during the early phase of germination.

    Science.gov (United States)

    Tsuji, Akihiko; Tsukamoto, Kana; Iwamoto, Keiko; Ito, Yuka; Yuasa, Keizo

    2013-01-01

    Papain-like cysteine protease activity that shows a unique transient expression profile in cotyledons of daikon radish during germination was detected. The enzyme showed a distinct elution pattern on DEAE-cellulose compared with cathepsin B-like and Responsive to dessication-21 cysteine protease. Although this activity was not detected in seed prior to imbibition, the activity increased markedly and reached a maximum at 2 days after imbibition and then decreased rapidly and completely disappeared after 5 days. Using cystatin-Sepharose, the 26 kDa cysteine protease (DRCP26) was isolated from cotyledons at 2 days after imbibition. The deduced amino acid sequence from the cDNA nucleotide sequence indicated that DRCP26 is an orthologue of Arabidopsis unidentified protein, germination-specific cysteine protease-1, belonging to the C1 family of cysteine protease predicted from genetic information. In an effort to characterize the enzymatic properties of DRCP26, the enzyme was purified to homogeneity from cotyledons at 48 h after imbibition. The best synthetic substrate for the enzyme was carbobenzoxy-Phe-Arg-4-methylcoumaryl-7-amide. All model peptides were digested to small peptides by the enzyme, suggesting that DRCP26 possesses broad cleavage specificity. These results indicated that DRCP26 plays a role in the mobilization of storage proteins in the early phase of seed germination.

  10. A sunflower WRKY transcription factor stimulates the mobilization of seed-stored reserves during germination and post-germination growth.

    Science.gov (United States)

    Raineri, Jesica; Hartman, Matías D; Chan, Raquel L; Iglesias, Alberto A; Ribichich, Karina F

    2016-09-01

    The sunflower transcription factor HaWRKY10 stimulates reserves mobilization in Arabidopsis. Gene expression and enzymes activity assays indicated that lipolysis and gluconeogenesis were increased. Microarray results suggested a parallelism in sunflower. Germinating oilseeds converts stored lipids into sugars, and thereafter in metabolic energy that is used in seedling growth and establishment. During germination, the induced lipolysis linked to the glyoxylate pathway and gluconeogenesis produces sucrose, which is then transported to the embryo and driven through catabolic routes. Herein, we report that the sunflower transcription factor HaWRKY10 regulates carbon partitioning by reducing carbohydrate catabolism and increasing lipolysis and gluconeogenesis. HaWRKY10 was regulated by abscisic acid and gibberellins in the embryo leaves 48 h after seed imbibition and highly expressed during sunflower seed germination and seedling growth, concomitantly with lipid mobilization. Sunflower leaf disks overexpressing HaWRKY10 showed repressed expression of genes related to sucrose cleavage and glycolysis compared with controls. Moreover, HaWRKY10 constitutive expression in Arabidopsis seeds produced higher decrease in lipid reserves, whereas starch and sucrose were more preserved compared with wild type. Gene transcripts abundance and enzyme activities involved in stored lipid mobilization and gluconeogenesis increased more in transgenic than in wild type seeds 36 h after imbibition, whereas the negative regulator of lipid mobilization, ABI4, was repressed. Altogether, the results point out a functional parallelism between tissues and plant species, and reveal HaWRKY10 as a positive regulator of storage reserve mobilization in sunflower.

  11. Effect of germination on the structures and physicochemical properties of starches from brown rice, oat, sorghum, and millet.

    Science.gov (United States)

    Li, Cheng; Oh, Sea-Gwan; Lee, Dong-Hyun; Baik, Hyun-Wook; Chung, Hyun-Jung

    2017-07-22

    Four selected grains (brown rice, oat, sorghum, and millet) were subjected to germinate and changes in granule morphology, molecular structure, crystalline structure, and physicochemical properties of isolated starch were investigated. The germinated starches showed pits and holes on the surface of the starch granules and the particle size distributions shifted slightly to smaller size as the germination time increased. Germination led to decrease in amylose content, while molecular weights of the germinated starches showed no significant changes. The relative crystallinity of all selected grain starches decreased significantly during germination. Compared to the native starches, the germinated starches had lower retrogradation enthalpy. Brown rice and oat starches exhibited marginal increases in peak viscosities, whereas those of sorghum and millet starches decreased significantly during germination. Amylose leaching of brown rice and oat starches decreased after germination, whereas sorghum and millet starches showed an increase in amylose leaching. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Development of a threshold model to predict germination of Populus tomentosa seeds after harvest and storage under ambient condition.

    Science.gov (United States)

    Wang, Wei-Qing; Cheng, Hong-Yan; Song, Song-Quan

    2013-01-01

    Effects of temperature, storage time and their combination on germination of aspen (Populus tomentosa) seeds were investigated. Aspen seeds were germinated at 5 to 30°C at 5°C intervals after storage for a period of time under 28°C and 75% relative humidity. The effect of temperature on aspen seed germination could not be effectively described by the thermal time (TT) model, which underestimated the germination rate at 5°C and poorly predicted the time courses of germination at 10, 20, 25 and 30°C. A modified TT model (MTT) which assumed a two-phased linear relationship between germination rate and temperature was more accurate in predicting the germination rate and percentage and had a higher likelihood of being correct than the TT model. The maximum lifetime threshold (MLT) model accurately described the effect of storage time on seed germination across all the germination temperatures. An aging thermal time (ATT) model combining both the TT and MLT models was developed to describe the effect of both temperature and storage time on seed germination. When the ATT model was applied to germination data across all the temperatures and storage times, it produced a relatively poor fit. Adjusting the ATT model to separately fit germination data at low and high temperatures in the suboptimal range increased the models accuracy for predicting seed germination. Both the MLT and ATT models indicate that germination of aspen seeds have distinct physiological responses to temperature within a suboptimal range.

  13. SDS-PAGE ANALYSIS OF PROTEINS FROM THE SEEDS OF HONEYLOCUST (GLEDITSIA TRIACANTHOS DURING GERMINATION

    Directory of Open Access Journals (Sweden)

    Eugen Ungureanu

    2007-08-01

    Full Text Available The main objective of the experiment was to observe the variety and evolution of the proteins during germination of the seeds from the honeylocust (Gleditsia triacanthos. Using the technique of SDS-PAGE there were discovered a lot of protein fractions. The profile of these fractions varies from the wide distribution along the entire molecular masses spectrum at the beginning of the germination to a poorly represented profile of protein fractions at the end of the germination.

  14. Spore Cortex Hydrolysis Precedes Dipicolinic Acid Release during Clostridium difficile Spore Germination

    OpenAIRE

    2015-01-01

    Bacterial spore germination is a process whereby a dormant spore returns to active, vegetative growth, and this process has largely been studied in the model organism Bacillus subtilis. In B. subtilis, the initiation of germinant receptor-mediated spore germination is divided into two genetically separable stages. Stage I is characterized by the release of dipicolinic acid (DPA) from the spore core. Stage II is characterized by cortex degradation, and stage II is activated by the DPA released...

  15. [Effects of fungi and its liquid extract on seed germination of Dendrobium hancockii Rolf].

    Science.gov (United States)

    Guo, S; Xu, J

    1990-07-01

    The experiment revealed that several species of fungi isolated from the protocorms of Orchidaceae notable promote the seed germination of Dendrobium hancockii. The seed germination rate amounts to over 20% when the seeds are incubated with fungi, but zero without incubation. Seed germination rate ranges from 40 to 70% when the incubation is affected in liquid extract of the cultural products of fungi, but the growth of protocorms and seedlings of Dendrobium hancockii is slower in liquid extract of fungi than on mycolia.

  16. Effects of Some Pre-Treatments on Seed Germination of Silk Tree (Albizia julibrissin)

    OpenAIRE

    Ertekin, Murat

    2010-01-01

    This study was conducted to break dormancy and enhancing germination of Albizia julibrissin seeds. In this study, effects of auxin (polystimulin A6), cytokinin (polystimulin K and indol-3-butric acid), gibberellin (GA3) and different stratification days on seed germination were investigated. With this aim, PS, IBA and GA3 hormones were used. Results indicated that the highest germination rate, which was 99%, was obtained by stratification at 30 days treatment, and soaking the seeds in 100 mg/...

  17. Sulfinylated Azadecalins act as functional mimics of a pollen germination stimulant in Arabidopsis pistils

    OpenAIRE

    Qin, Yuan; Wysocki, Ronald J.; Somogyi, Arpad; Feinstein, Yelena; Franco, Jessica Y.; Tsukamoto, Tatsuya; Dunatunga, Damayanthi; Levy, Clara; Smith, Steven; Simpson, Robert; Gang, David; Johnson, Mark A.; Palanivelu, Ravishankar

    2011-01-01

    Polarized cell elongation is triggered by small molecule cues during development of diverse organisms. During plant reproduction, pollen interactions with the stigma result in the polar outgrowth of a pollen tube, which delivers sperm cells to the female gametophyte to effect double fertilization. In many plants, pistils stimulate pollen germination. However, in Arabidopsis, the effect of pistils on pollen germination and the pistil factors that stimulate pollen germination remain poorly char...

  18. Effect of reduced light and low oxygen concentration on germination, growth and establishment of some plants

    DEFF Research Database (Denmark)

    Yasin, Muhammad

    Many abiotic factors effect plants germination, growth, and development. This Ph.D. study elucidates the effect of reduced light, low oxygen and seed dormancy on germination and growth of some weed species, field crops and vegetables. One study describes the growth and developmental responses of ...... improved the germination of the problematic invader Alliaria petiolate of North American forests. A method was developed to break seed dormancy of the herb garlic mustard using chemicals....

  19. A mathematical model for the germinal center morphology and affinity maturation

    CERN Document Server

    Meyer-Hermann, M

    2002-01-01

    During germinal center reactions the appearance of two specific zones is observed: the dark and the light zone. Up to now, the origin and function of these zones are poorly understood. In the framework of a stochastic and discrete model several possible pathways of zone development during germinal center reactions are investigated. The importance of the zones in the germinal center for affinity maturation, i.e. the process of antibody optimization is discussed.

  20. Seed germination and in vitro regeneration of the African medicinal and pesticidal plant, Bobgunnia madagascariensis

    OpenAIRE

    Thokozani, Blackson L.K.; Zulu, Donald; Gudeta W. Sileshi; Teklehaimanot, Zewge; Gondwe, Dominic S.B.; Sarasan, Viswambharan; Stevenson, Philip

    2011-01-01

    Propagation of the medicinal and pesticidal tree, Bobgunnia madagascarensis is difficult due to poor and erratic germination of its seeds and slow growth of its seedlings. This study involved two separate experiments. The first evaluated the effect of pre-sowing treatments and growing medium on ex vitro seed germination and early seedling development. The second experiment involved in vitro germination, shoot initiation and rooting of shoots. Pre-sowing seed treatments involved soaking seeds ...

  1. The effect of plant growth regulators on centaury (Centaurium erythraea Rafn) seeds germination

    OpenAIRE

    Mijajlović Nada; Grubišić Dragoljub V.; Giba Zlatko; Konjević Radomir

    2005-01-01

    Centaury seeds are light-requiring. Long-term red light irradiation caused more than 80% of seeds to germinate. Seeds did not germinate in darkness. Gibberellic acid and GA7 can replace light, but N-substituted phtalimide AC 94,377 was ineffective. Light-induced germination was inhibited by abscisic acid and growth retardants such as ancymidol, tetcyclacis, and paclobutrazole. Growth retardant-caused inhibition can be overcome by the addition of gibberellic acid.

  2. The effect of plant growth regulators on centaury (Centaurium erythraea Rafn seeds germination

    Directory of Open Access Journals (Sweden)

    Mijajlović Nada

    2005-01-01

    Full Text Available Centaury seeds are light-requiring. Long-term red light irradiation caused more than 80% of seeds to germinate. Seeds did not germinate in darkness. Gibberellic acid and GA7 can replace light, but N-substituted phtalimide AC 94,377 was ineffective. Light-induced germination was inhibited by abscisic acid and growth retardants such as ancymidol, tetcyclacis, and paclobutrazole. Growth retardant-caused inhibition can be overcome by the addition of gibberellic acid.

  3. Morphometric parameters and seed germination of Origanum vulgare L. grown in Crimean foothills

    Directory of Open Access Journals (Sweden)

    E.F. Myagkih

    2013-04-01

    Full Text Available The results of investigation shown that the seeds of Оriganum vulgareL. grown in the foothills of the Crimea are very small (1.8-1.9 mm long and 1.2-1.3 mm wide, weight of 1000 seeds is 0.079-0.089. In the first year after harvest the germination is highest and then it quickly decreases. In particular, the highest level of oregano germination was observed one month after harvesting. Some samples (Nr. 64 and 79 retained high germination potential (according the National Standard of Ukraine during 6 and 12 months. Further storage of seeds shown significant decreasing of germination.

  4. Effect of Some Stresses on Free Proline Content During Pigeonpea (Cajanas cajan Seed Germination

    Directory of Open Access Journals (Sweden)

    Bhamburdekar S.B.

    2011-09-01

    Full Text Available Plants accumulate proline under a variety of stress conditions thereby preventing stress-caused damages. The proline accumulation in germinating seeds of pigeonpea in response to NaCl, Boron and Aluminium treatments were studied. Results showed increased accumulation of proline in salinity stressed germinating seeds. As compare to 100 ppm boron, 10 and 50 ppm of boron treatments promoted proline levels at different stages of seed germination. The content of proline was found to be induced by all aluminium concentrations particularly at 48, 72 and 120 hrs. of seed germination. Whereas reverse pattern of proline accumulation was observed at 96 hrs stage under all studied stresses.

  5. The effect of temperature on germination of chlamydospores of Phytophthora ramorum.

    Science.gov (United States)

    Tooley, Paul W; Browning, Marsha; Leighty, Robert M

    2014-01-01

    Mycelium-free chlamydospores of 12 isolates of P. ramorum representing three clonal lineages were produced with a method involving incubation in nonsterile sand at 20 C in darkness for 30 d. Chlamydospores were incubated on selective agar medium at 5, 10, 15, 20, 25 and 30 C and germination assessed after 1, 2, 4, 6 and 8 d incubation. The optimal temperature for germination based on 8 d incubation was 20 C for all three clonal lineages tested (NA1, NA2, EU1). Mean germination rates were 2, 21, 44, 67, 32 and 0 percent at 5, 10, 15, 20, 25 and 30 C respectively for all isolates combined. The highest mean germination rate was scored by isolates of the EU1 clonal lineage at 20 C (85%) after 8 d incubation However, substantial variation was observed among isolates within each clonal lineage. Overall temperatures and days of incubation on which germination was assessed isolates of the NA1 clonal lineage had the lowest mean germination, even though one isolate had the highest germination of any isolate in any lineage. The results indicate that 20 C is the optimal germination temperature for P. ramorum chlamydospores and that a great disparity in germination percentage can exist within isolates, even within a single clonal lineage.

  6. Storage in cerrado soil and germination of Psychotria vellosiana (Rubiaceae seeds

    Directory of Open Access Journals (Sweden)

    C. G. Araújo

    Full Text Available The regeneration of plant communities from seed depends, to a large extent, on the capacity of the seed remaining viable in the soil. The viability and germination of artificially buried Psychotria vellosiana seeds in cerrado soil were studied, with the purpose of discovering some physio-ecological aspects of dispersed seeds and evaluating their potential to constitute a soil seed bank. Seed samples were placed in nylon envelopes and buried in the soil of a Cerrado reserve at two different depths and sites. Buried seeds were retrieved periodically and tested for germination along with dry-stored seeds. In general, there was a reduction in seed germination with storage time, both in soil and dry stored conditions, and in some assays exhumed seeds germinated faster than dry stored ones. In general the soil storage favoured seed viability of ungerminated seeds as compared to dry stored ones, with the seeds remaining partially viable after 10 months of storage. The lack of germination of viable seeds suggests that seeds showed true dormancy and/or required an extended time to germinate. It was observed that some seeds had germinated while buried and such in situ germination tended to increase with rainfall. The water availability in the soil might be a limiting factor for successful germination of P. vellosiana in the field, and the seeds may constitute a persistent soil seed bank in the cerrado as dispersed seeds remain viable in the soil until the following period of seed dispersal.

  7. Effects of light and temperature on seed germination in Cecropia hololeuca Miq. (Cecropiaceae

    Directory of Open Access Journals (Sweden)

    Godoi Simone

    2004-01-01

    Full Text Available Seeds of Cecropia hololeuca were submitted to regimes of constant and alternating temperatures, associated with photoperiods of white light, "shade light" and continuous darkness under controlled conditions in laboratory. Seeds did not germinate at constant temperatures of 10°C to 20°C and above 35°C. Seeds only germinated in the darkness when the temperature was alternated. "Shade light" inhibited germination. We concluded that the regime of alternating temperatures suppressed the light effects on seed germination of this species.

  8. [Germination of soybeans BR-13 and Paraná: effects on mineral constituents].

    Science.gov (United States)

    Ribeiro, M L; Ida, E I; de Oliveira, M C

    1997-12-01

    The objective of this work was to evaluate the effect of germination on the minerals constituents (calcium, phosphorus, magnesium, potassium, copper, iron, manganese and zinc) of soybean. For the assays the soybean cultivars-Glycine max (L) Merril-BR-13 and Paraná were used. These were germinated in camera of germination at 25 degrees C and 100% of moisture, from 0 to 72 hours, collecting the samples in intervals of 6 hours. The analysis of variance and comparison among the means indicated that the minerals constituents remained constant up to 72 hours of germination.

  9. [Effects of Pb2+ stress on seed germination & seedling growth of Rabdosia rubescens].

    Science.gov (United States)

    Kong, Si-Xin; Su, He; Zhan, Yan-Ting; Li, Hai-Kui; Cui, Xu-Sheng; Guo, Yu-Hai

    2014-11-01

    The seeds of Rabdosia rubescens were as the materials to research the impacts of different lead (Pb2+) concentrations(0, 135, 270, 540, 1 080 mg x L(-1)) on seed germination and seedling growth. The results show that: Low concentration of lead had no obvious effect on early germination of the seed, the germination vigor and germination speed were lightly higher but not significantly differed at the level of Pb concentration 135 mg x L(-1) with control group; Mid-high concentration of Pb solution (270-1 080 mg x L(-1)) significantly inhibited the seed germination and seedling growth, which reduced the seed germination rate, germination vigor, germination index, embryo root length and shoot length, growth index with increasing of Pb concentrations. There was a inhibitory effect on embryo shoot length and root length at mid-high lead concentrations stress, and stronger inhibitory effect on root , which was more sensitive than shoot to Pb stress(P germination rate and biomass fresh weight reducing 10%, is 195.18, 101.65 mg x L(-1).

  10. Modeling of fungal and bacterial spore germination under static and dynamic conditions.

    Science.gov (United States)

    Peleg, Micha; Normand, Mark D

    2013-11-01

    Isothermal germination curves, sigmoid and nonsigmoid, can be described by a variety of models reminiscent of growth models. Two of these, which are consistent with the percent of germinated spores being initially zero, were selected: one, Weibullian (or "stretched exponential"), for more or less symmetric curves, and the other, introduced by Dantigny's group, for asymmetric curves (P. Dantigny, S. P.-M. Nanguy, D. Judet-Correia, and M. Bensoussan, Int. J. Food Microbiol. 146:176-181, 2011). These static models were converted into differential rate models to simulate dynamic germination patterns, which passed a test for consistency. In principle, these and similar models, if validated experimentally, could be used to predict dynamic germination from isothermal data. The procedures to generate both isothermal and dynamic germination curves have been automated and posted as freeware on the Internet in the form of interactive Wolfram demonstrations. A fully stochastic model of individual and small groups of spores, developed in parallel, shows that when the germination probability is constant from the start, the germination curve is nonsigmoid. It becomes sigmoid if the probability monotonically rises from zero. If the probability rate function rises and then falls, the germination reaches an asymptotic level determined by the peak's location and height. As the number of individual spores rises, the germination curve of their assemblies becomes smoother. It also becomes more deterministic and can be described by the empirical phenomenological models.

  11. Does proximity to neighbours affect germination of spores of non-proteolytic Clostridium botulinum?

    Science.gov (United States)

    Webb, Martin D; Stringer, Sandra C; Le Marc, Yvan; Baranyi, József; Peck, Michael W

    2012-10-01

    It is recognised that inoculum size affects the rate and extent of bacterial spore germination. It has been proposed that this is due to spores interacting: molecules released from germinated spores trigger germination of dormant neighbours. This study investigated whether changes to the total number of spores in a system or proximity to other spores (local spore density) had a more significant effect on interaction between spores of non-proteolytic Clostridium botulinum strain Eklund 17B attached to defined areas of microscope slides. Both the number of spores attached to the slides and local spore density (number of spores per mm(2)) were varied by a factor of nine. Germination was observed microscopically at 15 °C for 8 h and the probability of, and time to, germination calculated from image analysis measurements. Statistical analysis revealed that the effect of total spore number on the probability of germination within 8 h was more significant than that of proximity to neighbours (local spore density); its influence on germination probability was approximately four-times greater. Total spore number had an even more significant affect on time to germination; it had a nine-fold greater influence than proximity to neighbours. The applied models provide a means to characterise, quantitatively, the effect of the total spore number on spore germination relative to the effect of proximity to neighbouring spores.

  12. [Study on geographical variation of morphologic and germination characteristic of different Glycyrrhiza uralensis provenance seeds].

    Science.gov (United States)

    Wei, Sheng-Li; Wang, Wen-Quan; Qin, Shu-Ying; Liu, Chang-Li; Zhang, Zhao-Ying; Di, Ming

    2008-04-01

    To study the geographical variation of morphologic and germination characteristic of different Glycyrrhiza uralensis provenance seeds, approach the geographical variation mode and ecology mechanism, and laid theoretical foundation for districting and allocating of G. uralensis seeds. Field investigation and laboratory analysis were applied. Seed shape and kilosseed weight were sampled randomly, germination rate germination force by general methods. The morphologic characteristic of G. uralensis seeds showed roughly longitude variation tendency that the seeds increased gradually from west to east. While the germination characteristic showed roughly altitude variation tendency that the seeds germination rate and germination force increased with the increase of the altitude, and the average germination rate was the same with the seeds morphologic characteristic. The results of analysis correlated with the climatic factors show that the morphologic characteristic of G. uralensis was positive correlated with annual rain-fall of the habitat, and the germination rate was quickened by drought, high temperature and strong sunshine. The morphologic and germination characteristic and of G. uralensis seeds present distinguished geographical variation, and the formation of the variation was related to the ecological environment in which the seed provenance adapted.

  13. Overcoming dormancy and determining optimal temperature for slender serradella seed germination

    Directory of Open Access Journals (Sweden)

    Rodrigo Ramos Lopes

    2015-12-01

    Full Text Available ABSTRACT The objective of this study was to identify the most efficient method for overcoming coat-imposed dormancy and determine the optimal germination temperature for Ornithopus pinnatus seeds. Treatments to overcome dormancy were: intact seeds; immersion in hot water at 60 ºC, followed by soaking in the same water (unheated/24 h; immersion in hot water at 90 ºC, followed by soaking in the same water (unheated/24 h; mechanical scarification; chemical scarification, H2SO4/5 min; and chemical scarification, H2SO4/10 min. Percentages were calculated for germinated, abnormal, dormant, and dead seeds. Optimal germination temperatures were calculated using eight constant temperatures (0, 5, 10, 15, 20, 25, 30, and 35 °C, with 8 h of light and 16 h of darkness. Germination rate, frequency, and synchronization index of germination were used as parameters to establish optimum temperature for germination. A completely randomized experimental design was used, with twelve repetitions of 100 seeds per treatment. Data obtained were subjected to analysis of variance and Tukey's test at a 5% significance level. O. pinnatus seeds exhibit dormancy caused by the seed coat's impermeability to water. Mechanical scarification was efficient in promoting seed germination. The species is stenothermal, meaning it cannot tolerate significant temperature variations. The germination rate of seeds was linearly dependent on temperature. Synchronization of the germination process is greater in the optimum temperature range, established between 15 and 20 °C.

  14. Effects of submergence in water on seed germination and vigor of the Copaifera lucens (Fabaceae) seedlings

    Institute of Scientific and Technical Information of China (English)

    Daniela Baldez Vidal; Isis Leite Andrade; Marcelo Schramm Mielke

    2014-01-01

    We analyzed the tolerance of Copaifera lucens seeds to sub-mersion in water to assess the use of this species for direct seeding in riparian forest restoration programs. Seeds were submerged in water for 2, 4, 8, 16 and 32 days or not submerged (control = 0 days of submer-gence). For the control and at the end of each period of submersion, germination and seedling vigor tests were carried out. For germination tests, seeds were sown in plastic pots containing sand and kept in labora-tory conditions. The percentage of seed germination, the germination rate and the average germination time were analyzed. For seedlings, total biomass, leaf area, leaf mass per area and leaf area ratio were analyzed. Submersion time drastically affected the dissolved oxygen content and seed germination. Between 4 and 8 days of submersion there was a de-crease from 83.8% to 15.6% in the germination percentage. No seed germination occurred after 16 days of submersion. Although there was a significant decrease in the percentage of seed germination between 4 and 8 days of submersion, seedling vigor was not affected. Seeds of this species were partially tolerant to submersion in water, suggesting that C. lucens is a promising species for direct seeding in riparian forest restora-tion projects.

  15. Germination strategies of two halophytes in Salt Desert of northwestern China

    Institute of Scientific and Technical Information of China (English)

    LI Li; ZHANG XiMing

    2007-01-01

    The effects of temperatures and salinities on germination of two halophytes, Kalidium capsicum and Suaeda physophora in northwestern China, were tested, and their seed size and seed production were compared. It was found that seed of Suaeda physophora germinate under 10℃, even about 0℃, and at a wide temperature range of 10-30℃. It showed about 50% germination in the concentration up to 0.7 mol/L NaCl; optimum germination temperature of Kalidium capsicum was between 20℃ and 30℃. The concentration of less than 0.3 mol/L NaCl inhibited absolutely its germination. Germination recovery was observed when salinities were reduced and total germination percentage exceeded 90%. Seeds of Kalidium capsicum showed no loss of viability while Suaeda physophora an annual loss of viability of 75% at room temperature. Mean weight of seeds of Suaeda physophora was about 8.5 times of Kalidium capsicum, whereas the number of seeds of the latter was more than 20 times of the former.Suaeda physophora was observed to be dependent on periodic precipitation in germination and seedling growth. It suggests the evident trace of the species with zonation pattern. On the other hand, the germination of Kalidium capsicum was affected by unpredictable rain and inundation. This species might be a type without zonation patterns in halophytes. It was concluded that both species are halophytes, but they are established successfully by different adaptation strategies in the early stage of life history.

  16. Role of nano-SiO2 in germination of tomato (Lycopersicum esculentum seeds Mill.)

    OpenAIRE

    Manzer H. Siddiqui; Al-Whaibi, Mohamed H.

    2013-01-01

    Agricultural biotechnology is very familiar with the properties of nanomaterial and their potential uses. Therefore, the present experiment was conducted to test the beneficial effects of nanosilicon dioxide (nSiO2: size- 12 nm) on the seed germination of tomato (Lycopersicum esculentum Mill. cv Super Strain B). Application of nSiO2 significantly enhanced the characteristics of seed germination. Among the treatments, 8 g L−1 of nSiO2 improved percent seed germination, mean germination time, s...

  17. DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

    Science.gov (United States)

    Graeber, Kai; Linkies, Ada; Steinbrecher, Tina; Mummenhoff, Klaus; Tarkowská, Danuše; Turečková, Veronika; Ignatz, Michael; Sperber, Katja; Voegele, Antje; de Jong, Hans; Urbanová, Terezie; Strnad, Miroslav; Leubner-Metzger, Gerhard

    2014-01-01

    Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMINATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapping experiments between Brassicaceae species we show that the DOG1-mediated dormancy mechanism is conserved. Biomechanical analyses show that this mechanism regulates the material properties of the endosperm, a seed tissue layer acting as germination barrier to control coat dormancy. We found that DOG1 inhibits the expression of gibberellin (GA)-regulated genes encoding cell-wall remodeling proteins in a temperature-dependent manner. Furthermore we demonstrate that DOG1 causes temperature-dependent alterations in the seed GA metabolism. These alterations in hormone metabolism are brought about by the temperature-dependent differential expression of genes encoding key enzymes of the GA biosynthetic pathway. These effects of DOG1 lead to a temperature-dependent control of endosperm weakening and determine the optimal temperature for germination. The conserved DOG1-mediated coat-dormancy mechanism provides a highly adaptable temperature-sensing mechanism to control the timing of germination. PMID:25114251

  18. Evidence on the Adaptive Recruitment of Chinese Cork Oak (Quercus variabilis Bl.: Influence on Repeated Germination and Constraint Germination by Food-Hoarding Animals

    Directory of Open Access Journals (Sweden)

    Yifeng Zhang

    2016-02-01

    Full Text Available In drought temperate forest, seedling recruitment is highly dependent on seed burial by native animal dispersers. To prolong seed storage, animals often take measures to impede seed germination. Aiming to understand the strategic balance between the natural seed germination and the role played by animals in the constraint germination procedures, we investigated the stages on the germinated acorns of Chinese cork oak (Quercus variabilis Bl. and the rodents’ behavior on the consequential delay in developmental processes of acorns in Mt. Taihangshan area of Jiyuan, Henan, China. The results showed that (1 Apodemus peninsulae Thomas excise radicles from germinated acorns before hoarding; (2 radicle-excised acorns re-germinate successfully if the excised radicle was un-lignified, but reverse if excised radicle was lignified; and (3 seedlings derived from radicle-excised acorns produce more lateral roots than that of sound acorns. We conclude that rodents take the radicle-excision behavior as a deliberate mechanism to slow the rapid germination of acorns; nevertheless, the acorns adaptively respond to this negative treatment and counteract the constraint from rodents by regermination to preserve the viability of the seeds. Consequently, this plays a significant role in forest recruitment. This study proves the new survival model of Chinese cork oak against animal predation, and will broaden theories of animal-forest interaction, forest succession and can be used as a meaningful venture to temperate forest restoration efforts.

  19. Studies on the physiology of Funaria hygrometrica spore germination. Part IV. The effect of blue and red light on the germination of spores

    Directory of Open Access Journals (Sweden)

    J. Krupa

    2015-05-01

    Full Text Available The effect of radiation with wave-lengths 654 nm and 425 nm on the germination of Funaria hydgrometrica spores has been studied. The wave-length bands used for the radiation treatment were employed for various durations and in various combinations. The effects of red and blue light were different in the individual phases of germination when after an inductive radiation treatment light in the 425 nm wave-length was supplied. Differences in the effect of red and blue light are observable in the "post-effects" land in the germination morphology.

  20. Transcription factors regulating B cell fate in the germinal centre.

    Science.gov (United States)

    Recaldin, T; Fear, D J

    2016-01-01

    Diversification of the antibody repertoire is essential for the normal operation of the vertebrate adaptive immune system. Following antigen encounter, B cells are activated, proliferate rapidly and undergo two diversification events; somatic hypermutation (followed by selection), which enhances the affinity of the antibody for its cognate antigen, and class-switch recombination, which alters the effector functions of the antibody to adapt the response to the challenge faced. B cells must then differentiate into antibody-secreting plasma cells or long-lived memory B cells. These activities take place in specialized immunological environments called germinal centres, usually located in the secondary lymphoid organs. To complete the germinal centre activities successfully, a B cell adopts a transcriptional programme that allows it to migrate to specific sites within the germinal centre, proliferate, modify its DNA recombination and repair pathways, alter its apoptotic potential and finally undergo terminal differentiation. To co-ordinate these processes, B cells employ a number of 'master regulator' transcription factors which mediate wholesale transcriptomic changes. These master transcription factors are mutually antagonistic and form a complex regulatory network to maintain distinct gene expression programs. Within this network, multiple points of positive and negative feedback ensure the expression of the 'master regulators', augmented by a number of 'secondary' factors that reinforce these networks and sense the progress of the immune response. In this review we will discuss the different activities B cells must undertake to mount a successful T cell-dependent immune response and describe how a regulatory network of transcription factors controls these processes.

  1. Hydration, sporoderm breaking and germination of Cupressus arizonica pollen.

    Science.gov (United States)

    Chichiriccò, G; Spanò, L; Torraca, G; Tartarini, A

    2009-05-01

    In vitro and in vivo rehydration and germination in Cupressus arizonica pollen were examined using light and scanning electron microscopy. Shed pollen has 12.6% water content, which reduced to 8.2% after dispersal, and this latter pollen survived for some months at room temperature and for years at -10 degrees C. Rehydration requires breaking of the sporoderm walls and depends on the composition and pH of the rehydration medium. Acidity restrains the breakage, while alkalinity promotes it. Pollen division follows exine shedding and requires the persistence of the mucilaginous layer; hence, pH values countering these outcomes prevent division. Division results in a large and a small cell separated by a callosic wall. A pollen tube develops from the innermost intine of the large cell, which is callosic, and extends into the mucilaginous middle intine. The percentage germination never exceeded 17% in all tested media. In vivo, pollen rehydrates and casts off the exine in the micropylar drop. Drop withdrawal brings pollen to the apical nucellar cells that degenerate in the meantime, and it leaves a deposit on the surface of the micropylar canal. After contaction of the nucellar cells, the pollen flattens and its mucilaginous layer shrinks and disappears. This occurs simultaneously with sealing of the micropylar canal. During this time, pollen divides asymmetrically without the callosic wall, and the larger cell develops a tube in the interface with the nucellus. Only some pollen grains accomplish adhesion to the nucellus and germinate. The in vitro and in vivo developmental stages are discussed.

  2. Glucose-induced inhibition of seed germination in Lotus japonicus is alleviated by nitric oxide and spermine.

    Science.gov (United States)

    Zhao, Min-Gui; Liu, Ruo-Jing; Chen, Lei; Tian, Qiu-Ying; Zhang, Wen-Hao

    2009-01-30

    Seed germination is sensitive to glucose (Glc), nitric oxide (NO) and polyamine (PA). To elucidate whether cross-talk among Glc, NO and PAs occurs in mediation of seed germination, effects of Glc, NO and spermine on seed germination of Lotus japonicus were studied. Glc retarded seed germination in a concentration-dependent manner. NO donor sodium nitroprusside (SNP) alleviated Glc-induced inhibition of seed germination, whereas the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (cPTIO) diminished the SNP-dependent alleviation of seed germination. These observations indicate that Glc may inhibit seed germination by interacting with NO signaling pathways. Exogenous spermine enhanced and the inhibitor of the spermine synthase, methylglyoxal-bis-guanyl hydrazone (MGBG), inhibited seed germination, respectively. Like SNP, spermine alleviated the Glc-induced inhibition of seed germination, whereas MGBG exaggerated the Glc-induced inhibition of seed germination. These results suggest that Glc may inhibit the spermine synthesis, leading to reductions in seed germination. NO scavenger and spermine synthase inhibitor diminished the SNP-induced alleviation of Glc-induced inhibition of seed germination. These findings reveal that both NO and spermine participate in the Glc-induced inhibition of seed germination in L. japonicus.

  3. Dipicolinic Acid Release by Germinating Clostridium difficile Spores Occurs through a Mechanosensing Mechanism

    Science.gov (United States)

    Francis, Michael B.

    2016-01-01

    ABSTRACT Classically, dormant endospores are defined by their resistance properties, particularly their resistance to heat. Much of the heat resistance is due to the large amount of dipicolinic acid (DPA) stored within the spore core. During spore germination, DPA is released and allows for rehydration of the otherwise-dehydrated core. In Bacillus subtilis, 7 proteins are encoded by the spoVA operon and are important for DPA release. These proteins receive a signal from the activated germinant receptor and release DPA. This DPA activates the cortex lytic enzyme CwlJ, and cortex degradation begins. In Clostridium difficile, spore germination is initiated in response to certain bile acids and amino acids. These bile acids interact with the CspC germinant receptor, which then transfers the signal to the CspB protease. Activated CspB cleaves the cortex lytic enzyme, pro-SleC, to its active form. Subsequently, DPA is released from the core. C. difficile encodes orthologues of spoVAC, spoVAD, and spoVAE. Of these, the B. subtilis SpoVAC protein was shown to be capable of mechanosensing. Because cortex degradation precedes DPA release during C. difficile spore germination (opposite of what occurs in B. subtilis), we hypothesized that cortex degradation would relieve the osmotic constraints placed on the inner spore membrane and permit DPA release. Here, we assayed germination in the presence of osmolytes, and we found that they can delay DPA release from germinating C. difficile spores while still permitting cortex degradation. Together, our results suggest that DPA release during C. difficile spore germination occurs though a mechanosensing mechanism. IMPORTANCE Clostridium difficile is transmitted between hosts in the form of a dormant spore, and germination by C. difficile spores is required to initiate infection, because the toxins that are necessary for disease are not deposited on the spore form. Importantly, the C. difficile spore germination pathway

  4. The site effect on germinability of mugwort (Artemisia vulgaris L. achenes

    Directory of Open Access Journals (Sweden)

    Jan Winkler

    2005-01-01

    Full Text Available Mugwort (Artemisia vulgaris L. extremely spreads on uncultivated agricultural land and expands to arable land. Three sites were chosen in the local area of Uherské Hradiště: field (arable land, balk (adjacent to arable land and rubble heap (distant from arable land. At each site, 50 plants were selected from which mature achenes were collected in 2002 and 2003. The achenes germinated in a laboratory at a room temperature and were subjected to various germination conditions. A part of them was exposed to the temperature of – 20 °C in a freezer, the other part was stored at a room temperature. The germination was carried out either on filter paper in Petri dishes or in 30 mm layer of siliceous sand. One part of the achenes germinated in daylight, the other part in Petri dishes in the dark. The achenes cultivated in siliceous sand were covered with a 5 mm layer of the sand. The results were statistically assessed using Unistat software, analysis of variance and methods of least significant differences (LSD. Total average germinability of mugwort achenes was 67,7 %. The differences in germinability of frozen (66,7 % and non-frozen (72,6 % achenes were not statistically significant. Germinability of the achenes that matured in 2003 (69,9 % was highly significantly higher than that of the achenes matured in 2002 (65,4 %. The achenes germinated highly significantly more (77,9 % in daylight as compared with those germinated in the dark (57,4 %. Germinability of the achenes that germinated in siliceous sand was highly significantly higher (70,7 % than of those that germinated in Petri dishes (64,7 %. Germinability of the achenes matured in the field (64,1 % was significantly lower in comparison with the germinability of the achenes from a balk (69,7 % and rubble heap (69,2 %. The results of germinability of the achenes that matured in a rubble heap and balk did not significantly differ.

  5. A Clostridium difficile-Specific, Gel-Forming Protein Required for Optimal Spore Germination

    Directory of Open Access Journals (Sweden)

    M. Lauren Donnelly

    2017-01-01

    Full Text Available Clostridium difficile is a Gram-positive spore-forming obligate anaerobe that is a leading cause of antibiotic-associated diarrhea worldwide. In order for C. difficile to initiate infection, its aerotolerant spore form must germinate in the gut of mammalian hosts. While almost all spore-forming organisms use transmembrane germinant receptors to trigger germination, C. difficile uses the pseudoprotease CspC to sense bile salt germinants. CspC activates the related subtilisin-like protease CspB, which then proteolytically activates the cortex hydrolase SleC. Activated SleC degrades the protective spore cortex layer, a step that is essential for germination to proceed. Since CspC incorporation into spores also depends on CspA, a related pseudoprotease domain, Csp family proteins play a critical role in germination. However, how Csps are incorporated into spores remains unknown. In this study, we demonstrate that incorporation of the CspC, CspB, and CspA germination regulators into spores depends on CD0311 (renamed GerG, a previously uncharacterized hypothetical protein. The reduced levels of Csps in gerG spores correlate with reduced responsiveness to bile salt germinants and increased germination heterogeneity in single-spore germination assays. Interestingly, asparagine-rich repeat sequences in GerG’s central region facilitate spontaneous gel formation in vitro even though they are dispensable for GerG-mediated control of germination. Since GerG is found exclusively in C. difficile, our results suggest that exploiting GerG function could represent a promising avenue for developing C. difficile-specific anti-infective therapies.

  6. Influence of hydrogel on germination of lettuce and onion seed at different moisture levels

    Directory of Open Access Journals (Sweden)

    Kateřina Pazderů

    2013-01-01

    Full Text Available The influence of Agrisorb (water solution 1, 3, 5 g/l on lettuce and onion seed germination was tested in different moisture conditions (30 ml and 15 ml of water in germination box. Variants with reduced water level germinated much more slowly (MGT parameter than standard variants, though differences in total germination at the end of the test were insignificant. Treated variants of lettuce seeds showed a statistically significant increase in germination energy (GE on the first day (GE1, both water levels, but a significant decrease on the second day (columns GE2, 15 ml. Higher doses of Agrisorb slowed lettuce seed germination (GE2, 30 ml, dose 5 g significantly, similarly see GE2 (15 ml, doses 1, 3, 5 g. This slowdown was apparent for GE3 (both water amount as well. A similar but insignificant effect was evident for onions. There was an influence of cultivar and seed vigour on sensitivity to water stress. The hydrogel application influenced germination of lettuce and onion seeds. Treated lettuce seeds germinated faster than non-treated control in the beginning of germination process. This effect was not recorded in case of slowly germinated onion seed lots. Although influence of Agrisorb was positive in the beginning, higher doses of hydrogel reduced germination energy of treated seed lots (for example GE2, GE4 of both crops in comparison with non-treated control. Higher doses of hydrogel caused longer MGT of lettuce and onion as well.

  7. IMPORTANCE OF STORAGE CONDITIONS AND SEED TREATMENT FOR SUNFLOWER HYBRIDS SEEDS GERMINATION

    Directory of Open Access Journals (Sweden)

    Goran Krizmanić

    2014-12-01

    Full Text Available In this research we have determined germination energy and germination of seeds of sunflower hybrids ‘Luka’ and ‘Apolon’, at the beginning of storage and 6, 12 and 18 months after of storage period (2011-2012 in the floor concrete storage at two different air temperatures and humidity (S-1: air temperature 15-18°C and relative air humidity 65-70% as well as in climate chamber (S-2: air temperature 10-12°C and relative air humidity 60-65%, stored in four treatments (Control: processed-untreated seed; T-1: treated with A.I. metalaxyl-M; T-2: treated with A.I. metalaxyl-M + A.I. imidacloprid and T-3: treated with A.I. metalaxyl-M + A.I. clothianidin. Based on the obtained results we have determined that sunflower hybrid ‘Luka’, compared to hybrid ‘Apolon’, in the given storage conditions and with the same seed treatment has 5-8% higher germination energy and seed germination and that in climate chamber both hybrids have 5-7% higher germination energy. Seed treatment of both sunflower hybrids with A.I. imidacloprid maximally reduced initial germination energy and seed germination in all tested periods and conditions of storage. On the average, natural seed, after 18 months of storage did not have better seed quality compared to seed treated with A.I. metalaxyl-M while other treatments had more significant influence on reduction of germination energy and seed germination, 6-15%. On the average, compared to other variants, seeds treated with A.I. metalaxyl-M after 18 months of storage in both storage conditions had higher germination energy by 4-15%, and seed germination by 2-12%.

  8. Germination Response of Four Alien Congeneric Amaranthus Species to Environmental Factors

    Science.gov (United States)

    Hao, Jian-Hua; Lv, Shuang-Shuang; Bhattacharya, Saurav; Fu, Jian-Guo

    2017-01-01

    Seed germination is the key step for successful establishment, growth and further expansion of population especially for alien plants with annual life cycle. Traits like better adaptability and germination response were thought to be associated with plant invasion. However, there are not enough empirical studies correlating adaptation to environmental factors with germination response of alien invasive plants. In this study, we conducted congeneric comparisons of germination response to different environmental factors such as light, pH, NaCl, osmotic and soil burials among four alien amaranths that differ in invasiveness and have sympatric distribution in Jiangsu Province, China. The data were used to create three-parameter sigmoid and exponential decay models, which were fitted to cumulative germination and emergence curves. The results showed higher maximum Germination (Gmax), shorter time for 50% germination (G50) and the rapid slope (Grate) for Amaranthus blitum (low-invasive) and A. retroflexus (high-invasive) compare to intermediately invasive A. spinosus and A. viridis in all experimental regimes. It indicated that germination potential does not necessarily constitute a trait that can efficiently distinguish highly invasive and low invasive congeners in four Amaranthus species. However, it was showed that the germination performances of four amaranth species were more or less correlated with their worldwide distribution area. Therefore, the germination performance can be used as a reference indicator, but not an absolute trait for invasiveness. Our results also confirmed that superior germination performance in wide environmental conditions supplementing high seed productivity in highly invasive A. retroflexus might be one of the reasons for its prolific growth and wide distribution. These findings lay the foundation to develop more efficient weed management practice like deep burial of seeds by turning over soil and use of tillage agriculture to control

  9. A Clostridium difficile-Specific, Gel-Forming Protein Required for Optimal Spore Germination

    Science.gov (United States)

    Donnelly, M. Lauren; Li, William; Li, Yong-qing; Hinkel, Lauren; Setlow, Peter

    2017-01-01

    ABSTRACT Clostridium difficile is a Gram-positive spore-forming obligate anaerobe that is a leading cause of antibiotic-associated diarrhea worldwide. In order for C. difficile to initiate infection, its aerotolerant spore form must germinate in the gut of mammalian hosts. While almost all spore-forming organisms use transmembrane germinant receptors to trigger germination, C. difficile uses the pseudoprotease CspC to sense bile salt germinants. CspC activates the related subtilisin-like protease CspB, which then proteolytically activates the cortex hydrolase SleC. Activated SleC degrades the protective spore cortex layer, a step that is essential for germination to proceed. Since CspC incorporation into spores also depends on CspA, a related pseudoprotease domain, Csp family proteins play a critical role in germination. However, how Csps are incorporated into spores remains unknown. In this study, we demonstrate that incorporation of the CspC, CspB, and CspA germination regulators into spores depends on CD0311 (renamed GerG), a previously uncharacterized hypothetical protein. The reduced levels of Csps in gerG spores correlate with reduced responsiveness to bile salt germinants and increased germination heterogeneity in single-spore germination assays. Interestingly, asparagine-rich repeat sequences in GerG’s central region facilitate spontaneous gel formation in vitro even though they are dispensable for GerG-mediated control of germination. Since GerG is found exclusively in C. difficile, our results suggest that exploiting GerG function could represent a promising avenue for developing C. difficile-specific anti-infective therapies. PMID:28096487

  10. Nutrient profile of porridge made from Eleusine coracana (L.) grains: effect of germination and fermentation.

    Science.gov (United States)

    Subastri, Ariraman; Ramamurthy, Chitteti; Suyavaran, Arumugam; Mareeswaran, Ramachandran; Mandal, Priyanka; Rellegadla, Sandeep; Thirunavukkarasu, Chinnasamy

    2015-09-01

    Porridge (koozh) is one of the traditional foods made from Eleusine coracana L. grains (Finger millet). It is a soft food prepared from processed (germinated & fermented) finger millet flour (FMF). However, in the modern world of fast food, koozh is usually prepared from non-processed (non-germinated & non-fermented) FMF. Hence, present study was undertaken to evaluate the macro and micro nutrient contents in koozh prepared from germinated (fermented & non-fermented) and non-germinated (fermented & non-fermented) FMF. Highest protein, carbohydrate and glycoprotein contents were found in koozh prepared from germinated & non-fermented FMF. The free amino acid contents are higher in germinated & fermented condition when compare to other preparations. No significant change was observed in the calorific value of all preparations. There is no statistical difference in macro-nutrients & micro-nutrients minerals such as calcium, iron, magnesium, manganese, phosphorous and zinc among all the preparations. However, copper content is higher in non-germinated condition, whereas selenium, silicon and sulphur are higher in germinated FMF when compared to others. Significant level of total phenol, total flavonoid and free radical scavenging activity was observed in all preparations, which increased further during fermentation. The present observations, lead us to conclude that koozh prepared from germinated & non-fermented FMF contains higher level of carbohydrate, protein and glycoprotein, however germinated & fermented koozh has increased aminoacids, phytochemicals and free radical scavenging activity. Hence it is suggested that the consumption of koozh made from germinated & fermented FMF may provide easily digestible and energetic nutrients for healthier life.

  11. Campanulaceae: a family with small seeds that require light for germination.

    Science.gov (United States)

    Koutsovoulou, Katerina; Daws, Matthew I; Thanos, Costas A

    2014-01-01

    The Campanulaceae is a large cosmopolitan family, but is understudied in terms of germination, and seed biology in general. Small seed mass (usually in the range 10-200 µg) is a noteworthy trait of the family, and having small seeds is commonly associated with a light requirement. Thus, the purpose of this study was to investigate the effect of light on germination in 131 taxa of the Campanulaceae family, from all five continents of its distribution. For all taxa, seed germination was tested in light (8 or 12 h photoperiod) and continuous darkness under constant and alternating temperatures. For four taxa, the effect of light on germination was examined over a wide range of temperatures on a thermogradient plate, and the possible substitution of the light requirement by gibberellic acid and nitrate was examined in ten taxa. For all 131 taxa, seed germination was higher in light than in darkness for every temperature tested. Across species, the light requirement decreased significantly with increasing seed mass. For larger seeded species, germination in the dark reached higher levels under alternating than under constant temperatures. Gibberellic acid promoted germination in darkness whereas nitrates partially substituted for a light requirement only in species showing some dark germination. A light requirement for germination, observed in virtually all taxa examined, constitutes a collective characteristic of the family. It is postulated that smaller seeded taxa might germinate only on the soil surface or at shallow depths, while larger seeded species might additionally germinate when buried in the soil if cued to do so by fluctuating temperatures.

  12. Reactive oxygen species induced by cold stratification promote germination of Hedysarum scoparium seeds.

    Science.gov (United States)

    Su, Liqiang; Lan, Qinying; Pritchard, Hugh W; Xue, Hua; Wang, Xiaofeng

    2016-12-01

    Seed germination is comprehensively regulated by multiple intrinsic and extrinsic factors, and reactive oxygen species (ROS) are relatively new among these factors. However, the role and underlying mechanisms of ROS in germination regulation remain largely unknown. In this study, we initially found that cold stratification could promote germination and respiration of Hedysarum scoparium seeds, especially at low temperature. We then noted that a ROS environment change induced by hydrogen peroxide (H2O2) or methylviologen (MV) could similarly promote seed germination. On the other hand, the ROS scavenger N-acetyl-L-cysteine (NAC) suppressed germination of cold-stratified H. scoparium seeds, indicating a stimulatory role of ROS upon seed germination. An increased accumulation of O2(-) was detected in embryonic axes of cold-stratified seeds, and stratification-induced ROS generation as well as progressive accumulation of ROS during germination was further confirmed at the cellular level by confocal microscopy. Moreover, protein carbonylation in cold-stratified seeds was enhanced during germination, which was reversed by NAC treatment. Finally, the relationship between ROS and abscisic acid (ABA) or gibberellin (GA) in germination regulation was investigated. ABA treatment significantly inhibited germination and reduced the H2O2 content in both cold-stratified and non-cold-stratified seeds. Furthermore, we found that cold stratification mediates the down-regulation of the ABA content and increase of GA, suggesting an interaction between ROS and ABA/GA. These results in H. scoparium shed new light on the positive role of ROS and their cross-talk between plant hormones in seed germination. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Germination Response of Four Alien Congeneric Amaranthus Species to Environmental Factors.

    Science.gov (United States)

    Hao, Jian-Hua; Lv, Shuang-Shuang; Bhattacharya, Saurav; Fu, Jian-Guo

    2017-01-01

    Seed germination is the key step for successful establishment, growth and further expansion of population especially for alien plants with annual life cycle. Traits like better adaptability and germination response were thought to be associated with plant invasion. However, there are not enough empirical studies correlating adaptation to environmental factors with germination response of alien invasive plants. In this study, we conducted congeneric comparisons of germination response to different environmental factors such as light, pH, NaCl, osmotic and soil burials among four alien amaranths that differ in invasiveness and have sympatric distribution in Jiangsu Province, China. The data were used to create three-parameter sigmoid and exponential decay models, which were fitted to cumulative germination and emergence curves. The results showed higher maximum Germination (Gmax), shorter time for 50% germination (G50) and the rapid slope (Grate) for Amaranthus blitum (low-invasive) and A. retroflexus (high-invasive) compare to intermediately invasive A. spinosus and A. viridis in all experimental regimes. It indicated that germination potential does not necessarily constitute a trait that can efficiently distinguish highly invasive and low invasive congeners in four Amaranthus species. However, it was showed that the germination performances of four amaranth species were more or less correlated with their worldwide distribution area. Therefore, the germination performance can be used as a reference indicator, but not an absolute trait for invasiveness. Our results also confirmed that superior germination performance in wide environmental conditions supplementing high seed productivity in highly invasive A. retroflexus might be one of the reasons for its prolific growth and wide distribution. These findings lay the foundation to develop more efficient weed management practice like deep burial of seeds by turning over soil and use of tillage agriculture to control

  14. The Relation Between Endogenous Hormones and Late-Germination in Buds of Avrolles Apple

    Institute of Scientific and Technical Information of China (English)

    QIN Dong; WANG Jin-zheng; GUO Jian-min; ZHAI Heng

    2009-01-01

    In order to provide the physiological bases for selecting late-germination cultivars that can avoid late frost damage,the very late-germination variety Avrolles (Malus domestica) was used to study the relation between the dynamic changes and balance of endogenous hormones and germination time.The concentrations of endogenous GA3,ABA,IAA,and ZR were determined in buds of Avrolles and Judeline (Malus domestica) from dormancy releasing to germination by capillary electrophoresis.The dynamic changes of endogenous hormones concentration in buds of Avrolles and Judeline were similar; but the magnitude and time of the change were significantly different between the two varieties,especially for GA3.GA3 concentration increased with dormancy releasing,then decreased,and increased again before germination in the two varieties.GA3 concentration in Avrolles was 1.72 times that in Judeline at the first peak,the gap increased to 2.22 times at germination.ZR concentration exhibited a continuous increase trend,but it decreased sharply before germination.ZR accumulation in Avrolles took 36 days longer than in Judeline,the peak value was 44% higher than in Judeline.Before germination,ZR concentration in Avrolles was 2.12 times that in Judeline.The differences between IAA and ABA concentration were relatively small in the two varieties,while the ratios of GA3/ABA and (GA3 + IAA + ZR)/ABA in Avrolles were 2.08 and 1.58 times those in Judeline,respectively.The germination of apple bud was regulated by the endogenous hormones.For the late-germination apple Avrolles,its germination requires higher concentration of GA3 and ZR,which leads to the high ratios of GA3/ABA and (GA3 + IAA + ZR)/ABA.

  15. Isolation of bacterial endophytes from germinated maize kernels.

    Science.gov (United States)

    Rijavec, Tomaz; Lapanje, Ales; Dermastia, Marina; Rupnik, Maja

    2007-06-01

    The germination of surface-sterilized maize kernels under aseptic conditions proved to be a suitable method for isolation of kernel-associated bacterial endophytes. Bacterial strains identified by partial 16S rRNA gene sequencing as Pantoea sp., Microbacterium sp., Frigoribacterium sp., Bacillus sp., Paenibacillus sp., and Sphingomonas sp. were isolated from kernels of 4 different maize cultivars. Genus Pantoea was associated with a specific maize cultivar. The kernels of this cultivar were often overgrown with the fungus Lecanicillium aphanocladii; however, those exhibiting Pantoea growth were never colonized with it. Furthermore, the isolated bacterium strain inhibited fungal growth in vitro.

  16. Deoxyribonucleic acid synthesis and deoxynucleotide metabolism during bacterial spore germination.

    Science.gov (United States)

    Setlow, P

    1973-06-01

    Deoxyribonucleic acid (DNA) synthesis during germination of Bacillus megaterium spores takes place in two stages. In stage I (0-55 min) DNA synthesis is slow and there is no detectable net synthesis, whereas in stage II (from 55 min on) the rate of synthesis is much faster and net DNA synthesis occurs. Deoxyribonucleotide pool sizes match the rates of DNA synthesis in stages I and II. The level of deoxyribonucleotide triphosphates is not correlated with the level of deoxyribonucleotide kinases, but rather with that of ribonucleotide reductase activity.

  17. Changes of Limiting Dextrinase in Germinating Process of Malting Barley

    Institute of Scientific and Technical Information of China (English)

    LIANG Xiu-mei; LI Fen; WANG Hong-zhen; WANG Xing-zhi

    2002-01-01

    Based on five different species of barley, the foot layer analytic method was used to examine the activity and heat-resistance of the limiting dextrinase. The study was conducted on the dynamic changes of several types of the dextrinase in barley germinating process, the effect of temperature on the dextrinase and the divergence of dextrinase in different barley variety. The probability of the dextrinase that as reference index is used for screening and evaluating beer barley was discussed. The importance of dextrinase in brewing and its significant function was also discussed.

  18. Lipids characterization of ultrasound and microwave processed germinated sorghum.

    Science.gov (United States)

    Hassan, Sadia; Imran, Muhammad; Ahmad, Nazir; Khan, Muhammad Kamran

    2017-06-27

    Cereal crops and oilseeds provide diverse pool of fatty acids with characteristic properties. Sorghum (Sorghum bicolor (L.) Moench) provides the staple food with serving as main source of energy and protein. Germination of sorghum generally increases the nutritive value of seeds and the effects of germination on lipids composition of seeds vary greatly with processing conditions. Therefore, the current study was conducted to compare the effect of emerging processing techniques such as ultrasound (US) and microwave (MW) on fatty acids composition and oil yield of sorghum seeds before and after germination. Initially sorghum grains were soaked with 5% NaOCl (sodium hypochlorite) for surface sterilization. Afterwards, grains were soaked in excess water for 22 h at room temperature and were divided into four portions. The first portion (100 g grains) was subjected to germination without applying any microwave and ultrasonic treatment (T0). Second portion was further divided into four groups (T1, T2, T3, T4) (100 g of each group) and grains were subjected to ultrasonic treatments using two different ultrasonic intensities (US1: 40%; US2: 60%) within range of 0-100% and with two different time durations (tUS1: 5 min; tUS2: 10 min) at constant temperature. Third portion was also divided into four groups (T1, T2, T3, T4) (100 g of each group) and exposed to microwave treatments at two different power levels (MW1: 450 watt; MW2: 700 watt) within the range of 100-900 W for two different time durations (tMW1: 15 s; tMW2: 30s). Similarly, fourth portion was divided into four groups (T1, T2, T3, T4) (100 g of each group). Each group was exposed to both MW (MW1, MW2) (100-900 watt power) & US (US1, US2) (0-100% intensity) treatments at two different time levels (tUS, tMW). Then, germination was carried out and pre-treated raw and pre-treated germinated sorghum grains were analyzed for total oil yield, fatty acid composition and unsaturated fatty acids (Un

  19. Spore Heat Activation Requirements and Germination Responses Correlate with Sequences of Germinant Receptors and with the Presence of a Specific spoVA(2mob) Operon in Foodborne Strains of Bacillus subtilis

    NARCIS (Netherlands)

    Krawczyk, Antonina O.; de Jong, Anne; Omony, Jimmy; Holsappel, Siger; Wells-Bennik, Marjon H. J.; Kuipers, Oscar P.; Eijlander, Robyn T.

    Spore heat resistance, germination, and outgrowth are problematic bacterial properties compromising food safety and quality. Large interstrain variation in these properties makes prediction and control of spore behavior challenging. Highlevel heat resistance and slow germination of spores of some

  20. Germinant-enhanced decontamination of Bacillus spores adhered to iron and cement-mortar drinking water infrastructures.

    Science.gov (United States)

    Szabo, Jeffrey G; Muhammad, Nur; Heckman, Lee; Rice, Eugene W; Hall, John

    2012-04-01

    Germination was evaluated as an enhancement to decontamination methods for removing Bacillus spores from drinking water infrastructure. Germinating spores before chlorinating cement mortar or flushing corroded iron was more effective than chlorinating or flushing alone.

  1. Gene expression programs during Brassica oleracea seed maturation, osmopriming and germination process and the stress tolerance level

    NARCIS (Netherlands)

    Soeda, Y.; Konings, M.C.J.M.; Vorst, O.F.J.; Houwelingen, van A.M.M.L.; Stoopen, G.M.; Maliepaard, C.A.; Kodde, J.; Bino, R.J.; Groot, S.P.C.; Geest, van der A.H.M.

    2005-01-01

    During seed maturation and germination, major changes in physiological status, gene expression, and metabolic events take place. Using chlorophyll sorting, osmopriming, and different drying regimes, Brassica oleracea seed lots of different maturity, stress tolerance, and germination behavior were cr

  2. Irrigational impact of untreated and treated brewery-distillery effluent on seed germination of marigold (Tagetes erecta L.).

    Science.gov (United States)

    Sharma, Anuradha; Malaviya, Piyush

    2016-01-01

    Current study presents the effect of irrigation with different concentrations (20, 40, 60, 80 and 100%) of untreated and treated brewery-distillery effluent on germination behaviour of marigold (Tagetes erecta L. var. Pusa Basanti). The 100% untreated effluent showed acidic pH (4.80) and higher values of BOD (1500.00 mg l(-1)), COD (4000.00 mg l(-1)), chloride (1742.20 mg l(-1)), TSS (900.00 mg l(-1)) as compared to that of treated effluent. Tagetes seeds were exposed to different concentrations of effluent and the results revealed maximum values of germination parameters viz., percent germination, peak value, germination value, germination index, speed of germination and vigour index at 20% untreated and 60% treated effluent concentrations, whereas the values for negative germination parameters viz., delay index, germination period and percent inhibition were minimum at 20% untreated and 60% treated effluent concentrations.

  3. Does passage time through the lizard Podarcis lilfordi's guts affect germination performance in the plant Withania frutescens?

    Science.gov (United States)

    Castilla, Aurora M.

    2000-03-01

    I tested predictions of the hypothesis that a longer seed passage time through the gut of the lizard Podarcis lilfordi enhances germination performance in the plant Withania frutescens. I compared germination success and germination time between seeds that were ingested by lizards and control seeds that were not. I also explored relationships between natural variation in seed passage time and germination performance. Germination success did not differ between ingested (63 %) and non-ingested seeds (56 %); there was no significant relationship between germinability and retention time. Germination time did not differ between ingested and non-ingested seeds, and was unrelated to retention time. Hence, I found no support for the hypothesis that prolonged retention times should improve germination performance. In addition, this is a pilot study stressing the importance of reptiles as seed dispersers, at least in certain habitats.

  4. Identification of two peanut germin-like genes and the potential superoxide dismutase activity

    Science.gov (United States)

    Germin and germin-like protein (GLP) genes are members of large multigene families. These genes have been reported to play a role directly or indirectly in plant defense response. A number of GLPs have been demonstrated to have superoxidase dismutase (SOD) or oxalate oxidase (OxO) activity, leading ...

  5. Inter-specific variation in salinity effects on germination in Pacific Northwest tidal wetland plants

    Science.gov (United States)

    Environmental stressors such as salinity may affect plant germination and early growth, eventually impacting the distribution and abundance of more mature individuals. In a lab study we evaluated germination sensitivity to salinity in 13 tidal wetland species found in the Pacific...

  6. In Vitro Pollen Viability and Pollen Germination in Cherry Laurel (Prunus laurocerasus L.

    Directory of Open Access Journals (Sweden)

    Melekber Sulusoglu

    2014-01-01

    Full Text Available Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.. Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride and IKI (iodine potassium iodide, were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2 = 0.0614 and r2 = 0.0015, resp.. Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  7. Germination and Seedling Development of Seeds from Different Parkia biglobosa (Jacq G. Don Trees

    Directory of Open Access Journals (Sweden)

    Christiana O. ADEYEMI

    2013-02-01

    Full Text Available The effect of daylight, continuous illumination and acid scarification on the seed germination and seedling vegetative growth (epicotyl and hypocotyl lengths, and number of secondary roots of different Parkia biglobosawere investigated in the Plant Physiology Laboratory University of Ilorin, Ilorin Kwara State Nigeria. Seeds from two out of the twenty six Parkia tree samples (trees B and T germinated within 24 hours of planting in the daylight germination study while seeds from another tree (Q did not germinate until the third week after planting (3WAP. Some seeds have higher germination percentage both in the daylight (preliminary germination study and in the continuous light (illuminated study. The treatment with concentrated Sulphric acid (conc. H2SO4was effective in breaking the seed dormancy as seeds from eight (8 trees produced one hundred percent (100% germination. At p= 0.05 the length of epicotyl and hypocoty1 lengths were significantly different as seedling vegetative growth were long in the seedlings from the daylight experiment than the continuous light experiment. The vegetative growths of the seedlings from the scarified seed were longer at 15min of scarification in all except in trees F and Z. It was observed that the time of scarification affect the both seed germination and seedling development.

  8. Differentially expressed genes associated with dormancy or germination of Arabidopsis thaliana seeds

    NARCIS (Netherlands)

    Toorop, P.E.; Barroco, R.M.; Engler, G.; Groot, S.P.C.; Hilhorst, H.W.M.

    2005-01-01

    Differential display analysis using dormant and non-dormant Arabidopsis thaliana (L.) Heynh seeds resulted in a set of genes that were associated with either dormancy or germination. Expression of the germination-associated genes AtRPL36B and AtRPL27B, encoding two ribosomal proteins, was

  9. Differentially expressed genes associated with dormancy or germination of Arabidopsis thaliana seeds

    NARCIS (Netherlands)

    Toorop, P.E.; Barroco, R.M.; Engler, G.; Groot, S.P.C.; Hilhorst, H.W.M.

    2005-01-01

    Differential display analysis using dormant and non-dormant Arabidopsis thaliana (L.) Heynh seeds resulted in a set of genes that were associated with either dormancy or germination. Expression of the germination-associated genes AtRPL36B and AtRPL27B, encoding two ribosomal proteins, was undetectab

  10. Epstein-Barr virus, the germinal centre and the development of Hodgkin's lymphoma

    NARCIS (Netherlands)

    Mohamed, Ghada; Vrzalikova, Katerina; Cader, Fathima Zumla; Vockerodt, Martina; Nagy, Eszter; Flodr, Patrik; Yap, Lee-Fah; Diepstra, Arjan; Kluin, Philip M.; Rosati, Stefano; Murray, Paul

    2014-01-01

    The relationship between Epstein-Barr virus (EBV) and the germinal centre (GC) of the asymptomatic host remains an enigma. The occasional appearance of EBV-positive germinal centres in some patients, particularly those with a history of immunosuppression, suggests that EBV numbers in the GC are subj

  11. Induction of lycopene and lycopene precursors in germinating cottonseedwith the substituted triethylamine compound MPTA

    Science.gov (United States)

    Treatment of dark germinating cottonseed (Gossypium hirsutum Acala cultivar) with 0.72 mM 2(4-methylphenoxy) triethylamine (MPTA) resulted in a 18-fold increase in carotenoid biosynthesis. In comparison to H2O treated control seed germinating in the dark that formed 8.4 ug/g fr wt of lutein and 1.6 ...

  12. The decision to germinate is regulated by divergent molecular networks in spores and seeds

    DEFF Research Database (Denmark)

    Vesty, Eleanor F.; Saidi, Younousse; Moody, Laura A.;

    2016-01-01

    , the role of abscisic acid and diterpenes (gibberellins) in germination assumed much greater importance as land plant evolution progressed. We conclude that the endogenous hormone signalling networks mediating germination in response to the environment may have evolved independently in spores and seeds...

  13. Examining Research Questions on Germination from the Perspective of Scientific Creativity

    Science.gov (United States)

    Demir Kaçan, Sibel

    2015-01-01

    This study was conducted with the participation of 31 pre-service science teachers. Participants were asked to develop various research questions on germination. The study aims to examine research questions on the subject germination from the perspective of scientific creativity. The research questions were examined using the fluency, science…

  14. Germination shifts of C3 and C4 species under simulated global warming scenario.

    Science.gov (United States)

    Zhang, Hongxiang; Yu, Qiang; Huang, Yingxin; Zheng, Wei; Tian, Yu; Song, Yantao; Li, Guangdi; Zhou, Daowei

    2014-01-01

    Research efforts around the world have been increasingly devoted to investigating changes in C3 and C4 species' abundance or distribution with global warming, as they provide important insight into carbon fluxes and linked biogeochemical cycles. However, changes in the early life stage (e.g. germination) of C3 and C4 species in response to global warming, particularly with respect to asymmetric warming, have received less attention. We investigated germination percentage and rate of C3 and C4 species under asymmetric (+3/+6°C at day/night) and symmetric warming (+5/+5°C at day/night), simulated by alternating temperatures. A thermal time model was used to calculate germination base temperature and thermal time constant. Two additional alternating temperature regimes were used to test temperature metrics effect. The germination percentage and rate increased continuously for C4 species, but increased and then decreased with temperature for C3 species under both symmetric and asymmetric warming. Compared to asymmetric warming, symmetric warming significantly overestimated the speed of germination percentage change with temperature for C4 species. Among the temperature metrics (minimum, maximum, diurnal temperature range and average temperature), maximum temperature was most correlated with germination of C4 species. Our results indicate that global warming may favour germination of C4 species, at least for the C4 species studied in this work. The divergent effects of asymmetric and symmetric warming on plant germination also deserve more attention in future studies.

  15. Differentially expressed genes associated with dormancy or germination of Arabidopsis thaliana seeds

    NARCIS (Netherlands)

    Toorop, P.E.; Barroco, R.M.; Engler, G.; Groot, S.P.C.; Hilhorst, H.W.M.

    2005-01-01

    Differential display analysis using dormant and non-dormant Arabidopsis thaliana (L.) Heynh seeds resulted in a set of genes that were associated with either dormancy or germination. Expression of the germination-associated genes AtRPL36B and AtRPL27B, encoding two ribosomal proteins, was undetectab

  16. Toward characterizing seed vigor in alfalfa through proteomic analysis of germination and priming.

    Science.gov (United States)

    Yacoubi, Rafika; Job, Claudette; Belghazi, Maya; Chaibi, Wided; Job, Dominique

    2011-09-02

    Alfalfa, the most widely grown leguminous crop in the world, is generally exposed to severe salinity stress in Tunisia, notably affecting its germination performance. Toward a better understanding of alfalfa seed vigor, we have used proteomics to characterize protein changes occurring during germination and osmopriming, a pretreatment that accelerates germination and improves seedling uniformity particularly under stress conditions. The data revealed that germination was accompanied by dynamic changes of 79 proteins, which are mainly involved in protein metabolism, cell structure, metabolism, and defense. Comparative proteomic analysis also revealed 63 proteins specific to osmopriming, 65 proteins preferentially varying during germination, and 14 proteins common to both conditions. Thus, the present study unveiled the unexpected finding that osmopriming cannot simply be considered as an advance of germination-related processes but involves other mechanisms improving germination such as the mounting of defense mechanisms enabling osmoprimed seeds to surmount environmental stresses potentially occurring during germination. The present results therefore provide novel avenues toward understanding the mechanisms of invigoration of low vigor seeds by priming treatments that are widely used both in commercial applications and in developing countries (on farm seed priming) to better control crop yields.

  17. [Effects of coat and sowing depth on seed germination and early seedling growth of Quercus wutaishanica].

    Science.gov (United States)

    Yan, Xing-Fui; Qiu, Zhi-Hu; Zhang, Qiang; Zhang, Kao-Wen; Zhou, Yun-Feng

    2014-01-01

    Under shade environment in glasshouse, the effects of seed coat and sowing depth (0, 2, 5, 10 or 15 cm) on seed germination and early seedling growth of Quercus wutaishanica were studied. Seed coat had obvious inhibiting effects on the germination of Q. wutaishanica seeds. The germination percentage of uncoated seeds increased significantly, averagely by 19.4% at different sowing depths. The germination index and vigor index were increased significantly and the germination was speeded in the peeling treatment. The germination percentages of uncoated and coated seeds were the highest at the sowing depth of 2 cm with 78.9% and 62.2%, respectively. The germination index and vigor index were the highest at the sowing depth of 2 cm, while the coefficient of rate of germination were the highest at the sowing depth of 5 cm. Leaf area per seedling and dry mass of seedlings increased significantly in the peeling treatment compared with those in the unpeeling treatment, but specific root length decreased significantly. The shoot height in the peeling and unpeeling treatments were the highest at the sowing depth of 5 cm with 13.8 and 14.2 cm, respectively. With the increasing of sowing depth, the basal stem diameter of seedlings increased, but tap-root length, number of lateral root and maximum of lateral root all decreased. Sowing depth had little influence on dry mass of seedlings.

  18. Anthrax Toxins in Context of Bacillus anthracis Spores and Spore Germination.

    Science.gov (United States)

    Cote, Christopher K; Welkos, Susan L

    2015-08-17

    The interaction of anthrax toxin or toxin components with B. anthracis spores has been demonstrated. Germinating spores can produce significant amounts of toxin components very soon after the initiation of germination. In this review, we will summarize the work performed that has led to our understanding of toxin and spore interactions and discuss the complexities associated with these interactions.

  19. Environmental effects on germination phenology of co-occurring eucalypts: implications for regeneration under climate change

    Science.gov (United States)

    Rawal, Deepa S.; Kasel, Sabine; Keatley, Marie R.; Nitschke, Craig R.

    2015-09-01

    Germination is considered one of the important phenological stages that are influenced by environmental factors, with timing and abundance determining plant establishment and recruitment. This study investigates the influence of temperature, soil moisture and light on the germination phenology of six Eucalyptus species from two co-occurring groups of three species representing warm-dry and cool-moist sclerophyll forests. Data from germination experiments were used to calibrate the germination module of the mechanistic model TACA-GEM, to evaluate germination phenology under a range of climate change scenarios. With the exception of E. polyanthemos, the optimal niche for all species was characterised by cool-moist stratification, low light, cool temperatures and high soil moisture. Model results indicated that of the warm-dry species, Eucalyptus microcarpa exhibited greater germination and establishment under projected changes of warmer drier conditions than its co-occurring species Eucalyptus polyanthemos and Eucalyptus tricarpa which suggests that E. microcarpa could maintain its current distribution under a warmer and drier climate in southeastern Australia. Among the cool-moist species, Eucalyptus radiata was the only species that established under projected climate change of the 2080s but at such a low probability that its persistence compared to Eucalyptus obliqua and Eucalyptus sieberi cannot be posited. For all cool-moist species, germination did not benefit from the phenological shifts they displayed. This study successfully demonstrated environmental effects on germination phenology and how a shift in climate can influence the timing and success of recruitment.

  20. 7 CFR 201.31 - Germination standards for vegetable seeds in interstate commerce.

    Science.gov (United States)

    2010-01-01

    ... interstate commerce. 201.31 Section 201.31 Agriculture Regulations of the Department of Agriculture... Germination standards for vegetable seeds in interstate commerce. The following germination standards for vegetable seeds in interstate commerce, which shall be construed to include hard seed, are determined...

  1. Interactions between ethylene, abscisic acid and cytokinin during germination and seedling establishment in Arabidopsis

    Indian Academy of Sciences (India)

    Veeraputhiran Subbiah; Karingu Janardhan Reddy

    2010-09-01

    In order to investigate the interaction of the plant hormones ethylene, abscisic acid (ABA) and cytokinin in seed germination and early seedling development, we studied germination in ethylene-related mutants of Arabidopsis. Mutations in the genes etr1 and ein2, which reduce ethylene responses, showed increased dormancy and a delay in germination in comparison with wild type. Mutations in etr1, ein2 and ein6 also resulted in increased sensitivity to ABA with respect to inhibition of germination. Conversely, mutations in ctr1 and eto3, which lead to an increased ethylene response and overproduction of ethylene, respectively, decreased sensitivity to ABA during germination. Increased ABA sensitivity was also effected in wild type seeds by the presence during germination of AgNO3, an inhibitor of ethylene action. The addition of the cytokinin N-6 benzyl adenine (BA) reversed the increased sensitivity of ethylene-resistant mutants to ABA. The action of cytokinin in reversing increased ABA sensitivity of ethylene-resistant mutants also suggests that at least part of the action of cytokinin in promoting germination is independent of its role in stimulating ethylene production. These observations further extend the evidence in support of interaction between ethylene, ABA and cytokinin signalling in controlling seed germination and early seedling development in Arabidopsis.

  2. Simulated seed predation reveals a variety of germination responses of neotropical rain forest species.

    Science.gov (United States)

    Vallejo-Marín, Mario; Domínguez, César A; Dirzo, Rodolfo

    2006-03-01

    Seed predation, an omnipresent phenomenon in tropical rain forests, is an important determinant of plant recruitment and forest regeneration. Although seed predation destroys large amounts of the seed crop of numerous tropical species, in many cases individual seed damage is only partial. The extent to which partial seed predation affects the recruitment of new individuals in the population depends on the type and magnitude of alteration of the germination behavior of the damaged seeds. We analyzed the germination dynamics of 11 tropical woody species subject to increasing levels of simulated seed predation (0-10% seed mass removal). Germination response to seed damage varied considerably among species but could be grouped into four distinct types: (1) complete inability to germinate under damage ≥1%, (2) no effect on germination dynamics, (3) reduced germination with increasing damage, and (4) reduced final germination but faster germination with increasing damage. We conclude that partial seed predation is often nonlethal and argue that different responses to predation may represent different proximal mechanisms for coping with partial damage, with potential to shape, in the long run, morphological and physiological adaptations in tropical, large-seeded species.

  3. WATER AND SODIUM CHLORIDE EFFECTS ON Mimosa Tenuiflora (WILLD. POIRET SEED GERMINATION

    Directory of Open Access Journals (Sweden)

    Ivonete Alves Bakke

    2006-01-01

    Full Text Available Water shortage and saline soils of the Brazilian semi-arid northeastern region are limiting factors to the development of many plants. Jurema preta (Mimosa tenuiflora (Willd. Poiret is a small, multiple use tree that abundantly colonizes unfavorable sites, including environments with severe water stress. This work had the objective of investigating the tolerance of jurema preta seeds to water and salt stresses during germination. Seeds germination in polyethylene glycol (PEG-6000 and sodium chloride (NaCl solutions was analyzed under five different osmotic potentials (0.0; -0.3, -0.6, -0.9 and -1.2MPa, in order to simulate water and salt stress, respectively, in four 100-seed replications for each treatment. Seeds were placed into 10cmx10cmx4cm boxes, and germination accomplished in BOD germinator adjusted to 30oC. The number of germinated seeds was monitored every 24 hours, and percentage and speed of seed germination were generated from these data. Mean percentage germination in the control treatment was ~95%, reducing to 63-53% at -0.9 to -1.2-MPa PEG solutions, and to 27- 9.5% at NaCl solutions at equivalent osmotic potentials. Velocity of germination index was more affected, and decreased up to 1/8 of the control, at -0.6 MPa. Jurema preta seeds showed lower tolerance to NaCl than to water stress, and this species can be classified as a glycophyte.

  4. Copper suppresses abscisic acid catabolism and catalase activity, and inhibits seed germination of rice.

    Science.gov (United States)

    Ye, Nenghui; Li, Haoxuan; Zhu, Guohui; Liu, Yinggao; Liu, Rui; Xu, Weifeng; Jing, Yu; Peng, Xinxiang; Zhang, Jianhua

    2014-11-01

    Although copper (Cu) is an essential micronutrient for plants, a slight excess of Cu in soil can be harmful to plants. Unfortunately, Cu contamination is a growing problem all over the world due to human activities, and poses a soil stress to plant development. As one of the most important biological processes, seed germination is sensitive to Cu stress. However, little is known about the mechanism of Cu-induced inhibition of seed germination. In the present study, we investigated the relationship between Cu and ABA which is the predominant regulator of seed germination. Cu at a concentration of 30 µM effectively inhibited germination of rice caryopsis. ABA content in germinating seeds under copper stress was also higher than that under control conditions. Quantitative real-time PCR (qRT-PCR) revealed that Cu treatment reduced the expression of OsABA8ox2, a key gene of ABA catabolism in rice seeds. In addition, both malondialdehyde (MDA) and H2O2 contents were increased by Cu stress in the germinating seeds. Antioxidant enzyme assays revealed that only catalase activity was reduced by excess Cu, which was consistent with the mRNA profile of OsCATa during seed germination under Cu stress. Together, our results demonstrate that suppression of ABA catabolism and catalase (CAT) activity by excess Cu leads to the inhibition of seed germination of rice.

  5. Aromatic A-ring analogues of orobanchol, new germination stimulants for seeds of parasitic weeds

    NARCIS (Netherlands)

    Malik, H.; Kohlen, W.; Jamil, M.; Rutjes, F.P.J.T.; Zwanenburg, B.

    2011-01-01

    Strigolactones are signaling compounds in plants of increasing importance. In this paper the focus is on their activity as germinating agents for seeds of parasitic weeds. The syntheses of aromatic A-ring analogues of the germination stimulant orobanchol have been described. Starting substrate is th

  6. Mechanical scarification in seeds of Morinda citrifolia aiming to speed up the process of germination

    Directory of Open Access Journals (Sweden)

    M. J. C. Gomes

    2013-07-01

    Full Text Available Abstract: Morinda Citrifolia are plants known as important properties with pharmacological and medicine, and the growth of this kind of plant has been increased in the last years. This work has as objective of developing different methods of seed germination of the Morinda citrifolia. The work was carried out in the laboratory of seed analyses at federal university of mato grosso, Sinop. The seeds were collected in plants of Bianchi farm. The material was benefited in the shade and stored in a container by 30 days. Used DIC as design, with treatment and 4 reprises; T1 witness; T2 with smashed seeds part; T3 seeds in water for 6 hours and T4 with smashed seeds part in water for 6 hours. For each treatment was studied with 4 reprises of 25 seeds, The seeds were treated with hypochlorite in 2%. The germination was conducted in special papers of germination, in greenhouse BOD at 30C. The tests of rate germination and speed was started in 24 hours after the installation of experiment. T1 and T3 doesnt present germination, the treatment T4 and presents germination between 42 % and 30% respective. T4 presented IUV of 1,77 and T2 of 2,77, been this treatments recommended for germination of Morinda citrifolia.Key words: Germination, numb, seeds.

  7. ÉMILE ZOLA: TRADUÇÕES DE L’ASSOMMOIR E GERMINAL NO BRASIL

    OpenAIRE

    Gomes, Mônica dos Santos

    2013-01-01

    Este artigo tem por objetivo a apresentação das traduções, publicadas no Brasil, dos romances L’Assommoir e Germinal. _______________________________________________________________________________________ ABSTRACT In this paper we present the translations, which were published in Brazil, of novels L’Assommoir and Germinal.

  8. Individual electrical conductivity test for the assessment of soybean seed germination

    Directory of Open Access Journals (Sweden)

    Nilson Matheus Mattioni

    2015-02-01

    Full Text Available Soybean seed quality is affected by many factors, which may occur during the production, processing, and storage phases. To ensure the quality of seeds, the adoption of fast and efficient methods to estimate seed viability in quality control programs is important. This study aimed to determine a partition point of the individual electrical conductivity test to predict soybean seed germination. Three lots each of five different soybean cultivars (Fundacep 57 RR, BMX Potência RR, BMX Força RR, BMX Turbo RR, and Nidera 7321 RG were used. Seed quality was assessed through the mass of 1,000 seeds (MTS, moisture content (MC, germination test (G, bulk electrical conductivity (BEC, individual electrical conductivity (IEC, accelerated ageing (AA, and field seedling emergence (FSE. To determine a partition point in the IEC test for predicting germination, seeds were subjected to the germination test in the same position used for the IEC test. The accuracy of the partition point was tested by comparing predicted germination with the standard germination test. The partition point obtained for normal seeds was 130 ?S .cm-1.seed-1. The IEC test, however, had limitations in predicting soybean seed germination. The data for predicted germination were different from those obtained by the standard test, because the characteristics of each lot led to differences in the electrical conductivity values.

  9. Effects of irrigation frequency and grit color on the germination of lodgepole pine seeds

    Science.gov (United States)

    Jeremy R. Pinto; R. Kasten Dumroese; Douglas R. Cobos

    2009-01-01

    Nursery cultural practices during germination can be highly variable between existing production facilities. Although nursery guidebooks suggest keeping seeds moist, there are no known scientific answers indicating what sufficient moisture levels are. This study objective was to characterize differing irrigation regimes and grit color choices on different germination...

  10. Evaluation of the effect of germination on phenolic compounds and antioxidant activities in Sorghum varieties

    NARCIS (Netherlands)

    Dicko, M.H.; Gruppen, H.; Traore, A.S.; Berkel, van W.J.H.; Voragen, A.G.J.

    2005-01-01

    The screening of 50 sorghum varieties showed that, on average, germination did not affect the content in total phenolic compounds but decreased the content of proanthocyanidins, 3-deoxyanthocyanidins, and flavan-4-ols. Independent of germination, there are intervarietal differences in antioxidant ac

  11. Mechanism of endocarp-imposed constraints of germination of Lannea microcarpa seeds

    NARCIS (Netherlands)

    Neya, O.; Hoekstra, F.A.; Golovina, E.A.

    2008-01-01

    Lannea microcarpa, a multipurpose tree species from the dry African savanna, sheds seeds that often display inhibition of germination. The underlying mechanism was investigated using seeds processed from fully matured fruits collected from natural stands in Burkina Faso. Germination of fresh seeds w

  12. [Study on morphology, quality and germination characteristics of Acanthopanax trifoliatus seeds under different habitats].

    Science.gov (United States)

    Xiao, Juan

    2014-05-01

    To preliminary explore the difference of the morphological, quality and germinal characteristics of Acanthopanax trifoliatus seeds under different habitats. Collect the wild seeds from different habitats in West Mountain, and then observe their external appearances and internal structure, and test the thousand seeds weight,water content and seed vigor. What's more, the influence to germination rates of the seeds from different temperatures and light intensities in artificial bioclimatic chamber was studied. Orthogonal test in experimental plots was carried out to screen the different sowing dates, matrix types and soil depths which may influence germination rate. The external appearances and quality characteristics of wild seeds from three habitats were different. Seeds could germinate in the both light and dark, the germination rate of the habitat II was as high as 70.5% at the optimum temperature 20 degrees C in artificial bioclimatic chamber. The optimal combination A1, B1, C1 was screened out through orthogonal test, namely, the germination rate would be the highest when the seeds sowed in autumn covering with 2 cm depth of matrix type which component of the ratio of soil, sand and organic fertilizer was 6: 3: 1. There was significant difference in the morphology and germination rate of the three habitats seeds. The habitat II seeds were the optimal choice when culture seedling. The influences of different temperatures on germination rate were different, and the dried seeds should sow in current autumn, better than the next spring.

  13. Photoperiod throughout the maternal life cycle, not photoperiod during seed imbibition, influences germination in Arabidopsis thaliana.

    Science.gov (United States)

    Imaizumi, Toshiyuki; Auge, Gabriela; Donohue, Kathleen

    2017-04-01

    Plants adjust their phenology in response to seasonal cues experienced both by their parents and by themselves, and coordinating responses to these cues is necessary for expressing adaptive phenology. We investigated how cues are integrated across time to influence an important progeny phenotype, i.e., seed germination. We used Arabidopsis thaliana to investigate how the photoperiod experienced by maternal parents and by progeny influences seed germination. We examined when maternal photoperiod effects on germination are imposed and how long they persist in progeny. The photoperiod experienced by maternal plants more strongly influenced germination than the photoperiod experienced during seed imbibition. In addition, the photoperiod experienced at the prereproductive stage frequently influenced germination as strongly as that experienced during reproduction. In general, seeds from plants grown under short days had higher seed germination percentages than seeds from plants grown in longer days. These maternal effects diminished with after-ripening, but reappeared in seeds induced into secondary dormancy. We found no evidence that the effect of photoperiod systematically attenuates in proportion to the time that elapsed between the cue and the timing of seed germination. Moreover, more recently experienced cues did not override the effects of cues experienced previously. Instead, specific sequences of photoperiods experienced at the prereproductive and reproductive stages appear to influence germination behavior. © 2017 Botanical Society of America.

  14. Germinal centre protein HGAL promotes lymphoid hyperplasia and amyloidosis via BCR-mediated Syk activation.

    Science.gov (United States)

    Romero-Camarero, Isabel; Jiang, Xiaoyu; Natkunam, Yasodha; Lu, Xiaoqing; Vicente-Dueñas, Carolina; Gonzalez-Herrero, Ines; Flores, Teresa; Garcia, Juan Luis; McNamara, George; Kunder, Christian; Zhao, Shuchun; Segura, Victor; Fontan, Lorena; Martínez-Climent, Jose A; García-Criado, Francisco Javier; Theis, Jason D; Dogan, Ahmet; Campos-Sánchez, Elena; Green, Michael R; Alizadeh, Ash A; Cobaleda, Cesar; Sánchez-García, Isidro; Lossos, Izidore S

    2013-01-01

    The human germinal centre-associated lymphoma gene is specifically expressed in germinal centre B-lymphocytes and germinal centre-derived B-cell lymphomas, but its function is largely unknown. Here we demonstrate that human germinal centre-associated lymphoma directly binds to Syk in B cells, increases its kinase activity on B-cell receptor stimulation and leads to enhanced activation of Syk downstream effectors. To further investigate these findings in vivo, human germinal centre-associated lymphoma transgenic mice were generated. Starting from 12 months of age these mice developed polyclonal B-cell lymphoid hyperplasia, hypergammaglobulinemia and systemic reactive amyloid A (AA) amyloidosis, leading to shortened survival. The lymphoid hyperplasia in the human germinal centre-associated lymphoma transgenic mice are likely attributable to enhanced B-cell receptor signalling as shown by increased Syk phosphorylation, ex vivo B-cell proliferation and increased RhoA activation. Overall, our study shows for the first time that the germinal centre protein human germinal centre-associated lymphoma regulates B-cell receptor signalling in B-lymphocytes which, without appropriate control, may lead to B-cell lymphoproliferation.

  15. Effects of spermine and spermidine on the germination of rice seeds under different temperatures

    Institute of Scientific and Technical Information of China (English)

    ZHUCheng; ZENGGuangwen

    1997-01-01

    Polyamine , including putrescine (Put) , spermidine(Spd), and spermine(Spm) , are a kind of regulating substances known extensively inhigher plants at present. Different results have been reported on the relationship between polyamines and seed germination (wheat, tobacco and potato). This study investigated the effects of spormine and spermidine on germination of rice seeds.

  16. Light regime and temperature on seed germination in Salvia hispanica L.

    Directory of Open Access Journals (Sweden)

    Emanoela Pereira de Paiva

    2016-09-01

    Full Text Available This study evaluated the effects of different light regimes and temperatures on the germination of S. hispanica seeds and used a factorial scheme in a completely randomized experimental design, in which three light conditions were combined with six temperatures (constant 20, 25, 30 and 35°C and alternating 20-30 and 25-30°C, totaling 18 treatments with four 50-seed replications. The seeds were sown on blotting paper in transparent plastic boxes and then allowed to germinate in Biochemical Oxygen Demand germinators. The seeds were evaluated over a period of eight days with respect to the following variables: germination percentage, average germination time, shoot and root lengths, shoot and root dry weights and root-shoot ratio. The data were submitted to Tukey’s test (p ≤ 0.05%. The S. hispanica seed (beige colored germination test can be carried out at constant (25°C or alternating (25-30°C temperatures. The germination of the seeds was indifferent to the light conditions evaluated; however, there was increased seedling growth and dry matter accumulation in the presence of light. The duration of the S. hispanica seed germination test can be five days, with the first count on the second day after sowing.

  17. Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes

    Science.gov (United States)

    Espinar, J.L.; Garcia, L.V.; Clemente, L.

    2005-01-01

    The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management.

  18. In Vivo Cell Wall Loosening by Hydroxyl Radicals during Cress Seed Germination and Elongation Growth

    NARCIS (Netherlands)

    Muller, K.; Linkies, A.; Vreeburg, R.A.M.; Fry, S.C.; Krieger-Liszkay, A.; Leubner-Metzger, G.

    2009-01-01

    Loosening of cell walls is an important developmental process in key stages of the plant life cycle, including seed germination, elongation growth, and fruit ripening. Here, we report direct in vivo evidence for hydroxyl radical (·OH)-mediated cell wall loosening during plant seed germination and se

  19. Effects of germination on chemical composition and functional properties of sesame (Sesamum indicum L.) seeds.

    Science.gov (United States)

    Hahm, Tae-Shik; Park, Sung-Jin; Martin Lo, Y

    2009-02-01

    The changes of chemical composition and functional properties of derooted sesame (Sesamum indicum L.) seeds (DSS) before, during, and after germination were investigated. Sesame seeds germinated in dark chambers maintained near 100% relative humidity at 35 degrees C without presoaking reached >99% germination rate in 4 days with the final moisture content stayed ca. 2% (w/w), characterizing sesame seeds as orthodox seeds that are suitable for long term storage at low temperature and humidity under defined environment. With noticeable reduction in fat content (23%), germinated DSS were found rich in linolenic acid, P, and Na, increasing from 0.38% (w/w), 445 mg/100 g, and 7.6 mg/100 g before germination to 0.81% (w/w), 472 mg/100 g, and 8.4 mg/100 g after germination, respectively. DSS after germination contained considerable amount of Ca (462 mg/100 g), higher than that of soybean. Germinated DSS presents an excellent source of sesamol (475 mg/100 g), a potent natural antioxidant, and alpha-tocopherol (32 mg/100 g), the most active form of vitamin E.

  20. Germination shifts of C3 and C4 species under simulated global warming scenario.

    Directory of Open Access Journals (Sweden)

    Hongxiang Zhang

    Full Text Available Research efforts around the world have been increasingly devoted to investigating changes in C3 and C4 species' abundance or distribution with global warming, as they provide important insight into carbon fluxes and linked biogeochemical cycles. However, changes in the early life stage (e.g. germination of C3 and C4 species in response to global warming, particularly with respect to asymmetric warming, have received less attention. We investigated germination percentage and rate of C3 and C4 species under asymmetric (+3/+6°C at day/night and symmetric warming (+5/+5°C at day/night, simulated by alternating temperatures. A thermal time model was used to calculate germination base temperature and thermal time constant. Two additional alternating temperature regimes were used to test temperature metrics effect. The germination percentage and rate increased continuously for C4 species, but increased and then decreased with temperature for C3 species under both symmetric and asymmetric warming. Compared to asymmetric warming, symmetric warming significantly overestimated the speed of germination percentage change with temperature for C4 species. Among the temperature metrics (minimum, maximum, diurnal temperature range and average temperature, maximum temperature was most correlated with germination of C4 species. Our results indicate that global warming may favour germination of C4 species, at least for the C4 species studied in this work. The divergent effects of asymmetric and symmetric warming on plant germination also deserve more attention in future studies.

  1. In vitro pollen viability and pollen germination in cherry laurel (Prunus laurocerasus L.).

    Science.gov (United States)

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r(2) = 0.0614 and r(2) = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  2. Proteomic analysis reveals key proteins and phosphoproteins upon seed germination of wheat (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Kun eDong

    2015-11-01

    Full Text Available Wheat (Triticum aestivum L. is one of the oldest cultivated crops and the second most important food crop in the world. Seed germination is the key developmental process in plant growth and development, and poor germination directly affects plant growth and subsequent grain yield. In this study, we performed the first dynamic proteome analysis of wheat seed germination using a two-dimensional differential gel electrophoresis (2D-DIGE-based proteomic approach. A total of 166 differentially expressed protein (DEP spots representing 73 unique proteins were identified, which are mainly involved in storage, stress/defense/detoxification, carbohydrate metabolism, photosynthesis, cell metabolism, and transcription/translation/ transposition. The identified DEPs and their dynamic expression profiles generally correspond to three distinct seed germination phases after imbibition: storage degradation, physiological processes/morphogenesis, and photosynthesis. Some key DEPs involved in storage substance degradation and plant defense mechanisms, such as globulin 3, sucrose synthase type I, serpin, beta-amylase, and plastid ADP-glucose pyrophosphorylase (AGPase small subunit, were found to be phosphorylated during seed germination. Particularly, the phosphorylation site Ser355 was found to be located in the enzyme active region of beta-amylase, which promotes substrate binding. Phosphorylated modification of several proteins could promote storage substance degradation and environmental stress defense during seed germination. The central metabolic pathways involved in wheat seed germination are proposed herein, providing new insights into the molecular mechanisms of cereal seed germination.

  3. Seed germination performances of Styrax species help understand their distribution in Cerrado areas in Brazil

    Directory of Open Access Journals (Sweden)

    Camila Kissmann

    2013-01-01

    Full Text Available In this descriptive paper, we described germination responses of Styrax pohlii, S. camporum and S. ferrugineus seeds at 5, 10, 15, 20, 25, 30, 35, 40 and 45 °C. We also assessed the percentage germination (%G of S. pohlii seeds with different seed water contents because, as a forest species, it seems to have recalcitrant seed behavior. Intrigued by the capacity of seeds of this species to germinate directly from puddles formed on poorly drained soils of riparian forests, where it typically occurs, we also tested the effect of de-pulping fruits on germination of S. pohlii seeds under hypoxia and normoxia conditions. In addition, we checked whether distinct concentrations of gibberellic acid (GA3 could break S. ferrugineus seed dormancy, a typical seed behavior of Cerrado species. No germination occurred at 5, 40 and 45 °C, regardless of the species. The optimal temperature for germination was 20 °C for S. pohlii and 25 °C for S. camporum. However, S. ferrugineus seeds showed a very low %G, regardless of the temperature, and GA3 could not consistently break possible physiological seed dormancy. For S. pohlii seeds, the higher the seed desiccation the lower the %G, and fruit pulp removal showed to be essential for seed germination. S. pohlii seeds germinated independently of oxygenation conditions.

  4. Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    Lizzy A. Mwamburi

    2015-03-01

    Full Text Available Three non-ionic surfactants: Tween20, Tween80 and Breakthru® were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassianaspore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations. Breakthru® had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25–30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses.

  5. Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana.

    Science.gov (United States)

    Mwamburi, Lizzy A; Laing, Mark D; Miller, Ray M

    2015-03-01

    Three non-ionic surfactants: Tween20, Tween80 and Breakthru (®) were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassiana spore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations . Breakthru (®) had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25-30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses.

  6. Germination of Phytophthora ramorum chlamydospores: a comparison of separation method and chlamydospore age

    Science.gov (United States)

    Justin P. Shaffer; Jennifer L. Parke

    2013-01-01

    Phytophthora ramorum characteristically produces large amounts of chlamydospores in vitro, but the role of these propagules in the disease cycle remains unclear. Germination is difficult to observe and quantify if chlamydospores are not free of mycelium, and the low frequency of germination commonly reported suggests that...

  7. Inhibition of spore germination of Alternaria tenuis by sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Couey, H.M.

    1962-08-01

    As a part of a continuing study of SO/sub 2/ fumigation of table grapes, the effect of SO/sub 2/ on spores of an isolate of A. tenuis Auct. causing decay of table grapes was determined. The amount of SO/sub 2/ required to inhibit completely spore germination depended on availability of moisture and the temperature. At 20/sup 0/C, wet spores required 20-min exposure to 100 ppm SO/sub 2/ to prevent germination, but spores equilibrated at 90% relative humidity (RH) required 10-min exposure to 1000 ppm SO/sub 2/. Dry spores at 60% RH were unaffected by a 20-min exposure to 4000 ppm SO/sub 2/. Increasing the temperature in the range 5-20/sup 0/C increased effectiveness of the SO/sub 2/ treatment. A comparison of Alternaria with Botrytis cinerea Fr. (studied earlier) showed that wet spores of these organisms were about equally sensitive to SO/sub 2/, but that dry Alternaria spores were more resistant to SO/sub 2/ than dry Botrytis spores under comparable conditions.

  8. Arabinan Metabolism during Seed Development and Germination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Leonardo D. Gomez; Clare G. Steele-King; Louise Jones; Jonathan M. Foster; Supachai Vuttipongchaikij; Simon J. McQueen-Mason

    2009-01-01

    Arabinans are found in the pectic network of many cell walls, where, along with galactan, they are present as side chains of Rhamnogalacturonan I. Whilst arabinans have been reported to be abundant polymers in the cell walls of seeds from a range of plant species, their proposed role as a storage reserve has not been thoroughly investigated. In the cell walls of Arabidopsis seeds, arabinose accounts for approximately 40% of the monosaccharide composition of non-cellulosic polysaccharides of embryos. Arabinose levels decline to ~ 15% during seedling establishment, indicating that cell wall arabinans may be mobilized during germination. Immunolocalization of arabinan in embryos, seeds, and seedlings reveals that arabinans accumulate in developing and mature embryos, but disappear during germination and seedling establishment. Experiments using ~(14)C-arabinose show that it is readily incorporated and metabolized in growing seed-lings, indicating an active catabolic pathway for this sugar. We found that depleting arabinans in seeds using a fungal arabinanase causes delayed seedling growth, lending support to the hypothesis that these polymers may help fuel early seedling growth.

  9. Phytotoxicity of nanoparticles: inhibition of seed germination and root growth.

    Science.gov (United States)

    Lin, Daohui; Xing, Baoshan

    2007-11-01

    Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC50) of nano-Zn and nano-ZnO were estimated to be near 50mg/L for radish, and about 20mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles.

  10. Effect on microorganisms of volatile compounds released from germinating seeds.

    Science.gov (United States)

    Schenck, S; Stotzky, G

    1975-10-01

    Volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source. Growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium. Volatiles caused increased growth of Pseudomonas fluorescens, Bacillus cereus, Erwinia carotovora, Agrobacterium tumefaciens, A. radiobacter, Rhizobium japonicum, Mucor mucedo, Fusarium oxysporum f. conglutinans, Trichoderma viride, and Penicillium vermiculatum but not of Sarcina lutea, Serratia marcescens, Chaetomium globosum, or Schizophyllum commune. Spores of Trichoderma viride showed higher germination in the presence of volatiles. Effects on growth were apparent only during the first 3 or 4 days after planting the seeds. Killed or dried seeds had no effect. The volatiles did not support microbial growth in the absence of nitrogen nor did they supply growth factors. Passing volatiles through KMnO4 or hydrazone reduced growth of the bacteria, indicating that oxidizable organic compounds, primarily aldehydes, were the active components. The volatiles were not absorbed by sterile soil, clay minerals, or water, but they were absorbed by non-steril soil and activated charcoal.

  11. Urethral metastasis of lung carcinoma with germinative cell features

    Directory of Open Access Journals (Sweden)

    Tefilli Marcos V.

    2003-01-01

    Full Text Available INTRODUCTION: We present the case of a patient with urethral metastasis of a lung carcinoma with germinative cell features. CASE REPORT: A White, 57-year old man underwent urologic assessment due to gross hematuria. Patient was being treated with chemotherapy and radiotherapy during the past 3 months due to primary carcinoma of the lung with brain metastasis. Urethrocistoscopy and nuclear magnetic resonance imaging revealed a stenosing mass invading the bulbomembranous urethra. No other tumor was found. Biopsy specimens, obtained from the lung, brain and urethra tumors, revealed the same neoplasia, with definitive diagnosis being undifferentiated giant cell carcinoma of the lung with germinative features. Considering his clinical condition and poor prognosis, a decision was made to treat the patient only clinically. Clinical conditions deteriorated and the patient evolved to death within 3 months. COMMENTS: As far as we were able to access, urethral metastasis from lung carcinoma had never been described in the indexed literature. Due to the extremely limited experience with these tumors, there is not a defined treatment and the prognosis remains quite poor.

  12. Efficient transformation of Rhizopus delemar by electroporation of germinated spores.

    Science.gov (United States)

    Xu, Sha; Zhou, Zhengxiong; Du, Guocheng; Zhou, Jingwen; Chen, Jian

    2014-08-01

    High efficient transformation of mycelial fungi is essential to both metabolic engineering and physiological analysis of these industrially important microorganisms. However, transformation efficiencies for mycelial fungi are highly restricted by difficulties in colony formation and competent cell preparation. In this work, an innovative transformation procedure that could significantly improve the efficiency of colony formation and transformation process has been established for a typical mycelial fungus, Rhizopus delemar. Single colonies of R. delemar were obtained with the addition of sodium deoxycholate. Fresh germinated spores of R. delemar were successfully transformed by electroporation. In addition, by pretreatment of the germinated spores with 0.05M lithium acetate (LiAc) and 20mM dithiothreitol (DTT) before electroporation, the transformation efficiency was further improved by 9.5-fold. The final transformation efficiency at optimal conditions reached 1239 transformants/μg DNA. The method described here would facilitate more efficient metabolic engineering and investigation of physiological functions in R. delemar or other similar mycelial fungi.

  13. Effects of Soil Temperature, Moisture, and Burial Depths on Carpogenic Germination of Sclerotinia sclerotiorum and S. minor

    OpenAIRE

    Subbarao, Krishna V.

    2008-01-01

    Extensive studies have been conducted on the carpogenic germination of Sclerotinia sclerotiorum, but carpogenic germination in S. minor has not been studied adequately. It remains unclear why apothecia of this pathogen have seldom been observed in nature. In this study, a new method was developed to produce apothecia in the absence of soil or sand, and carpogenic germination without preconditioning was recorded for 95 of the 96 S. sclerotiorum isolates tested. Carpogenic germination of the tw...

  14. DEVELOPMENTAL CHANGES IN THE GERMINATION, GROWTH AND CHLOROPHYLLASE ACTIVITY OF VIGNA MUNGO L. USING SEAWEED EXTRACT OF ULVA RETICULATA FORSSKAL.

    Directory of Open Access Journals (Sweden)

    Ganapathy Selvam G.

    2013-01-01

    Full Text Available The effect of seaweed extract prepared from Ulva reticulata on seed germination, seedling growth and chlorophyllase activity of Vigna mungo L. was studied. 100% germination was recorded in the seeds treated with lower concentration of seaweed extract. The V. mungo seeds soaked with lower concentrations of the seaweed extracts showed higher rates of germination, while the higher concentrations of the extracts inhibited the germination.

  15. Monitoring Rates and Heterogeneity of High-Pressure Germination of Bacillus Spores by Phase-Contrast Microscopy of Individual Spores

    Science.gov (United States)

    2014-01-01

    SECURITY CLASSIFICATION OF: The germination of multiple individual Bacillus subtilis spores by a high pressure (HP) of 140-150 (unless noted...otherwise) megaPascals (MPa) that activates spore germinant receptors (GRs) was monitored by phase contrast microscopy in a diamond anvil cell. Major...conclusions were that: i) >95% of spores germinated in 40 min; ii) individual spore’s HP germination kinetics were very similar to those for nutrient

  16. The decision to germinate is regulated by divergent molecular networks in spores and seeds

    DEFF Research Database (Denmark)

    Vesty, Eleanor F.; Saidi, Younousse; Moody, Laura A.

    2016-01-01

    in the model bryophyte Physcomitrella patens (Aphanoregma patens). Our data suggest that the environmental signals regulating germination are conserved, but also that downstream hormone integration pathways mediating these responses in seeds were acquired after the evolution of the bryophyte lineage. Moreover......Dispersal is a key step in land plant life cycles, usually via formation of spores or seeds. Regulation of spore- or seed-germination allows control over the timing of transition from one generation to the next, enabling plant dispersal. A combination of environmental and genetic factors determines...... when seed germination occurs. Endogenous hormones mediate this decision in response to the environment. Less is known about how spore germination is controlled in earlier-evolving nonseed plants. Here, we present an in-depth analysis of the environmental and hormonal regulation of spore germination...

  17. Inhibitory effect of marine green algal extracts on germination of Lactuca sativa seeds.

    Science.gov (United States)

    Choi, Jae-Suk; Choi, In Soon

    2016-03-01

    The allelopathic potential of nine green seaweed species was examined based on germination and seedling growth of lettuce (Lactuca sativa L.). Out of nine methanol extracts, Capsosiphon fulvescens and Monostroma nitidum extracts completely inhibited germination of L. sativa at 4 mg/filter paper after 24 hr of treatment. Water extracts of these seaweeds generally showed low anti-germination activities than methanol extracts. Of the nine water extracts, Enteromorpha linza extract completely inhibited L. sativa germination at 16 mg/filter paper after 24 hrs. To identify the primary active compounds, C. fulvescens. powder was successively fractionated according to polarity, and the main active agents against L. sativa were determined to be lipids (0.0% germination at 0.5 mg of lipids/paper disc). According to these results, extracts of C. fulvescens can be used to develop natural herbicidal agents and manage terrestrial weeds.

  18. Factors influencing germination and growth of isolated embryos of Pinus heldreichii

    Directory of Open Access Journals (Sweden)

    Stojičić Dragana

    2008-01-01

    Full Text Available The effects of nutritional, hormonal, and physical factors on the germination and growth of isolated mature zygotic embryos of Pinus heldreichii were studied under in vitro conditions. The optimum medium for embryo germination and adequate conversion into seedlings was basal Gresshoff and Doy (1GD medium. All tested carbohydrates at the applied concentrations stimulated embryo growth, but only 3% sucrose increased embryo germination compared to the control, while maltose had an inhibitory effect. Among the applied plant growth regulators, only gibberelic acid (GA3 had a few benefits on the development of isolated embryos into plantlets, while the others had a negative effect. Embryos cultured on an agar-solidified medium grew better and the germination percentage was higher than in a liquid medium. Light treatment did not affect embryo germination, but generally stimulated seedling growth.

  19. Methods of Seed Germination Stimulation Exemplified by Seeds of Honey Locust (Gleditsia triacanthos

    Directory of Open Access Journals (Sweden)

    Vasichkina Ekaterina Vladimirovna

    2014-02-01

    Full Text Available Seed germination is a difficult process in some cases because these seeds are covered by a firm testa. The firm testa should be destroyed by means of the following agricultural practices: scarification, stratification, impregnation in boiling water, etc. to increase seed germination. The application of different agricultural practices such as pulse pressure 11 MPa and 29 MPa, scarification, stratification, impregnation in boiling water, the treatment by suspension of rhizosphere microorganism V. paradoxus on seed germination of honey locust were discussed in this article. It was found that scarification, stratification and impregnation in boiling water are effective methods of the firm testa seeds treatment. These methods increased the percentage of seed germination significantly. In addition, seeds with natural cracks had high percentage of germination.

  20. A theory of germinal center B cell selection, division, and exit.

    Science.gov (United States)

    Meyer-Hermann, Michael; Mohr, Elodie; Pelletier, Nadége; Zhang, Yang; Victora, Gabriel D; Toellner, Kai-Michael

    2012-07-26

    High-affinity antibodies are generated in germinal centers in a process involving mutation and selection of B cells. Information processing in germinal center reactions has been investigated in a number of recent experiments. These have revealed cell migration patterns, asymmetric cell divisions, and cell-cell interaction characteristics, used here to develop a theory of germinal center B cell selection, division, and exit (the LEDA model). According to this model, B cells selected by T follicular helper cells on the basis of successful antigen processing always return to the dark zone for asymmetric division, and acquired antigen is inherited by one daughter cell only. Antigen-retaining B cells differentiate to plasma cells and leave the germinal center through the dark zone. This theory has implications for the functioning of germinal centers because compared to previous models, high-affinity antibodies appear one day earlier and the amount of derived plasma cells is considerably larger.

  1. Mycoflora in Exhumed Seeds of Opuntia tomentosa and Its Possible Role in Seed Germination

    Directory of Open Access Journals (Sweden)

    María Esther Sánchez-Coronado

    2011-01-01

    Full Text Available The funicular cover of the Opuntia tomentosa seed limits imbibition; germination occurs only when the funicle is weakened or the funicular valve is removed. We investigated the role of fungi in funicular weakening and seed germination. Seeds that had been either buried in one of two sites or stored in the laboratory were germinated with and without a valve. Disinfected or nondisinfected seeds and their naked embryos were cultivated on agar or PDA. None of the 11 identified fungal genera grew on the disinfected control seeds or the embryos. The mycoflora present on disinfected and nondisinfected exhumed seeds suggest that the fungal colonization occurred in the soil and differed between the burial sites. Exhumed seeds with and without a valve germinated in high percentages, whereas only the control seeds without a valve germinated. Scanning electron micrographs showed that the hyphae penetrated, cracked, and eroded the funicular envelope of exhumed seeds.

  2. Effects of fruit collection date on Phillyrea latifolia L. seed germination.

    Science.gov (United States)

    Yücedağ, Cengiz; Gültekin, H Cemal

    2011-08-01

    This study was conducted to determine the effects of date of fruit collection on the germination of Phillyrea latifolia L. Fruits were collected between September and December of 2007, in Egirdir, Turkey. It was found that the one thousand seed weight for the species seeds was 400 g, with significant differences among dates of fruit collection. The highest germination percentage of 58% was obtained from the seeds collected on the ground from previous years on the 1st of September 2007. The seeds from crown on the 1st of September 2007 had a germination percentage of 42%. Moreover, seeds from crown on the 1st of November and December 2007 and 15th of October and November 2007 did not germinate. In conclusion, P. latifolia seeds collected on the ground from previous years could be sown in early autumn to obtain a high germination rate.

  3. Comparative Study on GA Treatment to Promote the Seed Germination of Different Eggplant Varieties

    Institute of Scientific and Technical Information of China (English)

    Shuchun MENG; Zhenzhou YU; Shunhua SONG; Lianping MA

    2015-01-01

    Eggplant (Solanum melongena L.) is the world's fourth largest vegetable crop, but the dormancy phenomenon is common. This experiment selected 7 vari-eties of eggplant, which are widely used in the production at present in Beijing area, including Jing Qie No.5, Jing Qie No.10, Jing Qie No.3, Jing Yan No.2, Damingqie, Kuaiyuanqie and Jingqie No.1. After sterilization with 1.2% hydrogen per-oxide for 5 minutes, the seeds were soaked with 300 mg/L GA for 30 minutes, and the test temperatures were in the range of 20-30 ℃. Experimental results showed that the germination rate of GA treatment increased the maximum of 18%, indicating GA treatment can promote seed germination. Meanwhile, GA treatment can improve the speed of germination of eggplant, and shorten germination days, so that it is conducive to rapid germination of seed after sowing.

  4. Amino Acids Content in Germinating Seeds and Seedlings from Castanea sativa L.

    Science.gov (United States)

    Desmaison, A M; Tixier, M

    1986-06-01

    During germination the chestnut (Castanea sativa L.) var ecotype 33 accumulates a large amount of asparagine in the cotyledons. This compound also accumulates in the growing axis:shoots and roots. In the cotyledons, gamma-aminobutyrate (GABA) represents a major amino compound during germination and early seedling growth. In young seedlings, 35 days old, arginine predominates over the other soluble amino acids, particularly in roots. Five enzymic activities involved in arginine and GABA have been measured in the storage organ of the seed: arginase and ornithine carbamyltransferase decrease during germination indicating the slowing down of the urea cycle. In contrast, ornithine aminotransferase increases. Glutamate decarboxylase is particularly active about 21 days after imbibition and GABA aminotransferase activity decreases during germination. These two activities are in good agreement with the likely transport of GABA from cotyledons to growing axis. Asparagine, arginine, and GABA are the three amino compounds obviously involved in the mobilization of nitrogen reserves in the germinating chestnut seeds Castanea sativa.

  5. Cystic degeneration of the telencephalic subependymal germinal layer in newborn infants.

    Science.gov (United States)

    De León, G A; Girling, D J

    1975-03-01

    Cystic lesions were found in the telencephalic germinal layer of 12 newborn babies. According to their location, the cysts could be divided into three groups: anterior, middle or thalamostriate, and posterior. The histological appearance of all cysts was essentially the same, but in three cases the germinal layer had a peculiar alveolar type of microcystic degeneration. A constant feature was the presence in the cyst wall of small white granulations composed of germinal cells and/or glial tissue. Cystic degeneration of the germinal layer was usually bilateral and sometimes quite extensive. After the involution of the germinal layer, these lesions are likely to persist as subependymal cysts, characterized by their specific location and the presence of glial granulations.

  6. Estimation of scavenging capacity of melatonin and other antioxidants: contribution and evaluation in germinated seeds.

    Science.gov (United States)

    Aguilera, Yolanda; Herrera, Teresa; Benítez, Vanesa; Arribas, Silvia M; López de Pablo, Angel L; Esteban, Rosa M; Martín-Cabrejas, María A

    2015-03-01

    Seven edible seeds for the levels of melatonin, phenolic compounds and their antioxidant capacity were evaluated during germination process. Radical scavenging parameters were also studied in standard antioxidants to understand their antiradical actions. Germination brought about significant increases of total phenol compounds in all edible seeds, showing red cabbage, radish and broccoli the highest contents (21.6, 20.4 and 16.4 mg GAE/g DW, respectively). The concentration of melatonin is greatly variable in edible seeds, exhibiting significant increases during germination. The highest levels were found in red cabbage (857 pg/g DW) radish (536 pg/g DW) and broccoli (439 pg/g DW). The germinated seeds which had the highest levels of polyphenols and melatonin were those that showed the most relevant antiradical activities (>97%). This information is valuable for the incorporation of red cabbage, radish and broccoli germinated seeds into the diet to promote potential health benefits.

  7. The effects of selected pre-treatments on germination of seeds of Oriental hornbeam (Carpinus orientalis).

    Science.gov (United States)

    Ozel, Halil Bariş

    2016-07-01

    In the present study, the effect of some pre-treatments implemented on seeds of Oriental hornbeam (Carpinus orientalis), which has wide geographical variation along Turkey on germination percentage values were investigated. For this purpose, 13 different pre-treatments were implemented to seeds obtained from 17 different populations. According to the obtained results (except control seeds), pre-treatments leading to lowest germination percentage value (8.1%) in Oriental hornbeam seeds was PT10: Keeping seeds for 90 min in sulfuric acid, while highest germination percentage (86.58%) has been obtained with pre-treatment PT13: Implementation of 40% dose of Baikal EM1 + Biohoumous mixture to the seeds, while lowest germination percentage (40.50%) was observed on seeds collected from P7 (Bartin-Kozcağiz) population, highest germination percentage was observed in seeds obtained from P17 (Artvin-Hopa) population.

  8. The decision to germinate is regulated by divergent molecular networks in spores and seeds

    DEFF Research Database (Denmark)

    Vesty, Eleanor F.; Saidi, Younousse; Moody, Laura A.

    2016-01-01

    Dispersal is a key step in land plant life cycles, usually via formation of spores or seeds. Regulation of spore- or seed-germination allows control over the timing of transition from one generation to the next, enabling plant dispersal. A combination of environmental and genetic factors determines...... when seed germination occurs. Endogenous hormones mediate this decision in response to the environment. Less is known about how spore germination is controlled in earlier-evolving nonseed plants. Here, we present an in-depth analysis of the environmental and hormonal regulation of spore germination...... in the model bryophyte Physcomitrella patens (Aphanoregma patens). Our data suggest that the environmental signals regulating germination are conserved, but also that downstream hormone integration pathways mediating these responses in seeds were acquired after the evolution of the bryophyte lineage. Moreover...

  9. valuation of Germination Characteristics for Hedysarum Criniferum Boiss in Alternative Temperature and Drought Stress Conditions

    Directory of Open Access Journals (Sweden)

    A. Shahbazi

    2016-05-01

    24-26 °C day-night and four drought levels (0, -2, -4, and -6 bar with three replications. According to the results, different levels of drought stress and alternative temperature had significant effects on germination percentage and germination speed of the species seeds (α=5%. The study showed that increasing temperature and drought levels leads to reducing the germination percentage and germination speed of the species. Higher germination percentage of H. criniferum seeds in different drought levels compared to alternative temperature levels of 24-26 °C indicated that this species is more sensitive to higher temperature than high levels of drought condition. Therefore, it could partly be concluded that the H. criniferum is a relatively drought resistance species.

  10. Asymbiotic germination, seedling development and plantlet propagation of Encyclia aff. oncidioides - an endangered orchid

    Directory of Open Access Journals (Sweden)

    Ewa Łojkowska

    2011-01-01

    Full Text Available In order to estimate the best germination conditions of Encyclia aff. oncidioides seeds, five different media (Fast, Knudson C modified by Vajrabhaya, Murashige and Skoog, PB2 and modified Vacin and Went with different concentrations of plant growth regulators such as benzyladenine (BA, naphthaleneacetic acid (NAA and gibberellic acid (GA3 were tested. No beneficial effect was observed when BA and NAA were applied to the germination medium and GA3 inhibited germination. The effect of light, activated charcoal, coconut water and casein hydrolysate on seed germination was also studied. The growth rate of seedlings on three different media supplemented with activated charcoal and plant growth regulators was checked. The applied plant growth regulators had no beneficial effect on the further growth of seedlings. Fast and PB2 media with 0.2% activated charcoal proved to be the best for E. aff. oncidioides seed germination, seedling development and plantlet propagation.

  11. cis-4-Cyclohexene-1,2-dicarboximide: Inhibitor of phytochrome-promoted seed germination.

    Science.gov (United States)

    Bewley, J D; Oaks, A

    1980-06-01

    cis-4-Cyclohexene-1,2-dicarboximide (CHDC) inhibits the germination of light-requiring seeds in both light and darkness but has no effect upon the germination of non-light-requiring seeds. In lettuce seeds, CHDC inhibits the action of far-red-absorbing form of phytochrome in breaking dormancy. This inhibition can be overcome by benzyladenine and red light together, but not by a combination of red light and gibberellic acid. Gibberellic acid-induced germination of lettuce seeds in darkness is inhibited also by CHDC. Embryos isolated from dark-imbibed lettuce seeds germinate on the inhibitor. CHDC was thought to be an "analogue" of cycloheximide, but it does not inhibit protein synthesis in lettuce seeds. Our results lead us to conclude that CHDC inhibits germination of seeds that require red light to break dormancy and interferes with some aspect of metabolism that is stimulated by far-red-absorbing form of phytochrome.

  12. Seed germination and life history syndromes in the California chaparral

    Science.gov (United States)

    Keeley, J.E.

    1991-01-01

    Syndromes are life history responses that are correlated to environmental regimes and are shared by a group of species (Stebbins, 1974). In the California chaparral there are two syndromes contrasted by the timing of seedling recruitment relative to wildfires. One syndrome, here called the fire-recruiter or refractory seed syndrome, includes species (both resprouting and non-resprouting) which share the feature that the timing of seedling establishment is specialized to the first rainy season after fire. Included are woody, suffrutescent and annual life forms but no geophytes have this syndrome. These species are linked by the characteristic that their seeds have a dormancy which is readily broken by environmental stimuli such as intense heat shock or chemicals leached from charred wood. Such seeds are referred to as “refractory” and dormancy, in some cases, is due to seed coat impermeability (such seeds are commonly called hardseeded), but in other cases the mechanism is unknown. Seeds of some may require cold stratification and/or light in addition to fire related stimuli. In the absence of fire related cues, a portion or all of a species’ seed pool remains dormant. Most have locally dispersed seeds that persist in the soil seed bank until the site burns. Dispersal of propagules is largely during spring and summer which facilitates the avoidance of flowering and fruiting during the summer and fall drought. Within a life form (e.g., shrub, suffrutescent, etc.), the seeds of these species have less mass than those of species with non-refractory seeds and this possibly reflects the environmental favorableness of the postfire environment for seedling establishment. Regardless of when fire occurs, germination is normally delayed until late winter or early spring. In the absence of fire, or other disturbance, opportunities for population expansion are largely lacking for species with this syndrome. The other syndrome, here called the fire-resister or non

  13. Structural features of sugars that trigger or support conidial germination in the filamentous fungus Aspergillus niger.

    Science.gov (United States)

    Hayer, Kimran; Stratford, Malcolm; Archer, David B

    2013-11-01

    The asexual spores (conidia) of Aspergillus niger germinate to produce hyphae under appropriate conditions. Germination is initiated by conidial swelling and mobilization of internal carbon and energy stores, followed by polarization and emergence of a hyphal germ tube. The effects of different pyranose sugars, all analogues of d-glucose, on the germination of A. niger conidia were explored, and we define germination as the transition from a dormant conidium into a germling. Within germination, we distinguish two distinct stages, the initial swelling of the conidium and subsequent polarized growth. The stage of conidial swelling requires a germination trigger, which we define as a compound that is sensed by the conidium and which leads to catabolism of d-trehalose and isotropic growth. Sugars that triggered germination and outgrowth included d-glucose, d-mannose, and d-xylose. Sugars that triggered germination but did not support subsequent outgrowth included d-tagatose, d-lyxose, and 2-deoxy-d-glucose. Nontriggering sugars included d-galactose, l-glucose, and d-arabinose. Certain nontriggering sugars, including d-galactose, supported outgrowth if added in the presence of a complementary triggering sugar. This division of functions indicates that sugars are involved in two separate events in germination, triggering and subsequent outgrowth, and the structural features of sugars that support each, both, or none of these events are discussed. We also present data on the uptake of sugars during the germination process and discuss possible mechanisms of triggering in the absence of apparent sugar uptake during the initial swelling of conidia.

  14. Insights into the molecular mechanism of RGL2-mediated inhibition of seed germination in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Stamm Petra

    2012-10-01

    Full Text Available Abstract Background Seed germination is of immense significance for agriculture and has been studied for centuries. Yet, our understanding of the molecular mechanisms underlying regulation of dormancy and germination is still in its infancy. Gibberellins are the key phytohormones that promote germination, and the DELLA protein RGL2 is the main signalling intermediate involved in this response. Germination is completely inhibited if functional RGL2 is overexpressed and/or stabilized; however, the molecular mechanisms of RGL2 function are still largely unknown. We therefore attempted to shed light onto some of the genetic events downstream of RGL2. Results Gene ontology of the transcriptome differentially regulated by RGL2, as well as extensive cross-comparison with other available microarray data indicates that RGL2-mediated inhibition of germination causes seeds to enter a state of dormancy. RGL2 also appears to differentially regulate a number of transcription factors, many of which are known to be involved in light- or phytohormone-mediated aspects of germination. A promoter analysis of differentially expressed genes identified an enrichment of several motifs that can be bound by specific transcription factors, for example GAMYB, ARF1, or Dof-type zinc fingers. We show that Dof-binding motifs indeed play a role in RGL2-mediated transcription. Using Chromatin Immunoprecipitation (ChIP, we show that RGL2 directly downregulates at least one cell wall modifying enzyme, which is predicted to constrain cell growth thereby leading to inhibition of seed germination. Conclusions Our results reveal that RGL2 controls various aspects of germination. Through the repression of cell wall modifying enzymes, cell growth is directly constrained to inhibit germination. Furthermore, RGL2 likely interacts with various types of proteins to regulate transcription, and differentially regulates several transcription factors. Collectively, our data indicate that

  15. DNA damage checkpoint kinase ATM regulates germination and maintains genome stability in seeds.

    Science.gov (United States)

    Waterworth, Wanda M; Footitt, Steven; Bray, Clifford M; Finch-Savage, William E; West, Christopher E

    2016-08-23

    Genome integrity is crucial for cellular survival and the faithful transmission of genetic information. The eukaryotic cellular response to DNA damage is orchestrated by the DNA damage checkpoint kinases ATAXIA TELANGIECTASIA MUTATED (ATM) and ATM AND RAD3-RELATED (ATR). Here we identify important physiological roles for these sensor kinases in control of seed germination. We demonstrate that double-strand breaks (DSBs) are rate-limiting for germination. We identify that desiccation tolerant seeds exhibit a striking transcriptional DSB damage response during germination, indicative of high levels of genotoxic stress, which is induced following maturation drying and quiescence. Mutant atr and atm seeds are highly resistant to aging, establishing ATM and ATR as determinants of seed viability. In response to aging, ATM delays germination, whereas atm mutant seeds germinate with extensive chromosomal abnormalities. This identifies ATM as a major factor that controls germination in aged seeds, integrating progression through germination with surveillance of genome integrity. Mechanistically, ATM functions through control of DNA replication in imbibing seeds. ATM signaling is mediated by transcriptional control of the cell cycle inhibitor SIAMESE-RELATED 5, an essential factor required for the aging-induced delay to germination. In the soil seed bank, seeds exhibit increased transcript levels of ATM and ATR, with changes in dormancy and germination potential modulated by environmental signals, including temperature and soil moisture. Collectively, our findings reveal physiological functions for these sensor kinases in linking genome integrity to germination, thereby influencing seed quality, crucial for plant survival in the natural environment and sustainable crop production.

  16. Sulfinylated azadecalins act as functional mimics of a pollen germination stimulant in Arabidopsis pistils.

    Science.gov (United States)

    Qin, Yuan; Wysocki, Ronald J; Somogyi, Arpad; Feinstein, Yelena; Franco, Jessica Y; Tsukamoto, Tatsuya; Dunatunga, Damayanthi; Levy, Clara; Smith, Steven; Simpson, Robert; Gang, David; Johnson, Mark A; Palanivelu, Ravishankar

    2011-12-01

    Polarized cell elongation is triggered by small molecule cues during development of diverse organisms. During plant reproduction, pollen interactions with the stigma result in the polar outgrowth of a pollen tube, which delivers sperm cells to the female gametophyte to effect double fertilization. In many plants, pistils stimulate pollen germination. However, in Arabidopsis, the effect of pistils on pollen germination and the pistil factors that stimulate pollen germination remain poorly characterized. Here, we demonstrate that stigma, style, and ovules in Arabidopsis pistils stimulate pollen germination. We isolated an Arabidopsis pistil extract fraction that stimulates Arabidopsis pollen germination, and employed ultra-high resolution electrospray ionization (ESI), Fourier-transform ion cyclotron resonance (FT-ICR) and MS/MS techniques to accurately determine the mass (202.126 Da) of a compound that is specifically present in this pistil extract fraction. Using the molecular formula (C10H19NOS) and tandem mass spectral fragmentation patterns of the m/z (mass to charge ratio) 202.126 ion, we postulated chemical structures, devised protocols, synthesized N-methanesulfinyl 1- and 2-azadecalins that are close structural mimics of the m/z 202.126 ion, and showed that they are sufficient to stimulate Arabidopsis pollen germination in vitro (30 μm stimulated approximately 50% germination) and elicit accession-specific response. Although N-methanesulfinyl 2-azadecalin stimulated pollen germination in three species of Lineage I of Brassicaceae, it did not induce a germination response in Sisymbrium irio (Lineage II of Brassicaceae) and tobacco, indicating that activity of the compound is not random. Our results show that Arabidopsis pistils promote germination by producing azadecalin-like molecules to ensure rapid fertilization by the appropriate pollen.

  17. Germination of sorghum grain results in significant changes in paste and texture properties.

    Science.gov (United States)

    Yi, Cuiping; Li, Yan; Ping, Junai

    2017-10-01

    The changes in sorghum [Sorghum bicolor (L.) Moench] proteins during germination and the resultant effects on the physicochemical properties of sorghum flour were studied using non-germinated grains as a control. Results showed that flour obtained from germinated sorghum grains had lower protein levels, higher protease levels, and higher free amino nitrogen content compared with the control. There was an increase in the albumin and globulin protein fractions and a decrease in kafirin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated that this decrease was the result of a decrease in γ-kafirins, while microscopy found that a continuous protein network was formed. Following the germination-associated protein changes, the viscosities of sorghum paste decreased with germination from a peak viscosity value of 1,324 rapid visco units (RVU) down to 727 RVU in white sorghum (WS), and from 1,549 RVU to 1,295 RVU in red sorghum (RS). The hardness of the sorghum gels was significantly enhanced after germination, with WS increasing from 1,640 g to 5,374 g and RS from 970 g to 5,529 g. Thus, the study revealed that germination decreased the viscosity of sorghum paste and increased the strength of sorghum gel by changing the content and structure of sorghum protein, making it possible to design new foods that require thickening and gelling using germinated sorghum. Germination triggers the protease system of sprouting seeds, leading to the breakdown of proteins into simpler forms that decrease the viscosity of sorghum paste and improve the strength of sorghum gel, allowing the use of germinated sorghum to design new foods that require thickening and gelling. © 2016 Wiley Periodicals, Inc.

  18. Small Heat Shock Proteins Can Release Light Dependence of Tobacco Seed during Germination1[OPEN

    Science.gov (United States)

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia

    2015-01-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. PMID:25604531

  19. Small heat shock proteins can release light dependence of tobacco seed during germination.

    Science.gov (United States)

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia; Hong, Choo Bong

    2015-03-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination.

  20. Exogenous gibberellins inhibit coffee (Coffea arabica cv. Rubi) seed germination and cause cell death in the embryo

    NARCIS (Netherlands)

    Silva, Da E.A.A.; Toorop, P.E.; Nijsse, J.; Bewley, J.D.; Hilhorst, H.W.M.

    2005-01-01

    The mechanism of inhibition of coffee (Coffea arabica cv. Rubi) seed germination by exogenous gibberellins (GAs) and the requirement of germination for endogenous GA were studied. Exogenous GA4+7 inhibited coffee seed germination. The response to GA4+7 showed two sensitivity thresholds: a lower one

  1. Predicting seed dormancy loss and germination timing for Bromus tectorum in a semi-arid environment using hydrothermal time models

    Science.gov (United States)

    Susan E. Meyer; Phil S. Allen

    2009-01-01

    A principal goal of seed germination modelling for wild species is to predict germination timing under fluctuating field conditions. We coupled our previously developed hydrothermal time, thermal and hydrothermal afterripening time, and hydration-dehydration models for dormancy loss and germination with field seed zone temperature and water potential measurements from...

  2. Self-inhibition of spore germination via reactive oxygen in the fungus Cladosporium cucumerinum, causal agent of cucurbit scab

    Science.gov (United States)

    Cladosporium cucumerinum spore germination in vitro depended on spore suspension density. Different fungal isolates displayed maximum germination at different spore concentrations. For one isolate, maximum spore density was observed at both 18 and 25 °C, although germination percentage increased sli...

  3. Integration of Auxin and Salt Signals by the NAC Transcription Factor NTM2 during Seed Germination in Arabidopsis1[W

    Science.gov (United States)

    Park, Jungmin; Kim, Youn-Sung; Kim, Sang-Gyu; Jung, Jae-Hoon; Woo, Je-Chang; Park, Chung-Mo

    2011-01-01

    Seed germination is regulated through elaborately interacting signaling networks that integrate diverse environmental cues into hormonal signaling pathways. Roles of gibberellic acid and abscisic acid in germination have been studied extensively using Arabidopsis (Arabidopsis thaliana) mutants having alterations in seed germination. Auxin has also been implicated in seed germination. However, how auxin influences germination is largely unknown. Here, we demonstrate that auxin is linked via the IAA30 gene with a salt signaling cascade mediated by the NAM-ATAF1/2-CUC2 transcription factor NTM2/Arabidopsis NAC domain-containing protein 69 (for NAC with Transmembrane Motif1) during seed germination. Germination of the NTM2-deficient ntm2-1 mutant seeds exhibited enhanced resistance to high salinity. However, the salt resistance disappeared in the ntm2-1 mutant overexpressing the IAA30 gene, which was induced by salt in a NTM2-dependent manner. Auxin exhibited no discernible effects on germination under normal growth conditions. Under high salinity, however, whereas exogenous application of auxin further suppressed the germination of control seeds, the auxin effects were reduced in the ntm2-1 mutant. Consistent with the inhibitory effects of auxin on germination, germination of YUCCA 3-overexpressing plants containing elevated levels of active auxin was more severely influenced by salt. These observations indicate that auxin delays seed germination under high salinity through cross talk with the NTM2-mediated salt signaling in Arabidopsis. PMID:21450938

  4. Effects of water potential on spore germination and viability of Fusarium species.

    Science.gov (United States)

    Palmero Llamas, D; de Cara Gonzalez, M; Iglesias Gonzalez, C; Ruíz Lopez, G; Tello Marquina, J C

    2008-11-01

    Germination of macroconidia and/or microconidia of 24 strains of Fusarium solani, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. sambucinum, F. oxysporum and F. proliferatum isolated from fluvial channels and sea beds of the south-eastern coast of Spain, and three control strains (F. oxysporum isolated from affected cultures) was studied in distilled water in response to a range of water potentials adjusted with NaCl. (0, -13.79, -41.79, -70.37, -99.56 and -144.54 bars). The viability (UFC/ml) of suspensions was also tested in three time periods (0, 24 and 48 h). Conidia always germinated in distilled water. The pattern of conidial germination observed of F. verticilloides, F. oxysporum, F. proliferatum, F. chlamydosporum and F. culmorum was similar. A great diminution of spore germination was found in -13.79 bars solutions. Spore germination percentage for F. solani isolates was maximal at 48 h and -13.79 bars with 21.33% spore germination, 16% higher than germination in distilled water. F. equiseti shows the maximum germination percentage in -144.54 bars solution in 24 h time with 12.36% germination. This results did not agree with those obtained in the viability test were maximum germination was found in distilled water. The viability analysis showed the great capacity of F. verticilloides strains to form viable colonies, even in such extreme conditions as -144.54 bars after 24 h F. proliferatum colony formation was prevented in the range of -70.37 bars. These results show the clear affectation of water potential to conidia germination of Fusaria. The ability of certain species of Fusarium to develop a saprophytic life in the salt water of the Mediterranean Sea could be certain. Successful germination, even under high salty media conditions, suggests that Fusarium spp. could have a competitive advantage over other soil fungi in crops irrigated with saline water. In the specific case of F. solani, water potential of -13.79 bars affected

  5. Accelerating Seed Germination and seedling development of Sorghum (Sorghum bicolor L. Moench) through hydro-priming

    Science.gov (United States)

    Dembele, S., Jr.

    2015-12-01

    Mali, a West Africa Sahelian country, is characterized by a strong dependence on rain-fed agriculture and a low adaptive capacity, making it one of the most vulnerable regions to climate change worldwide. Moreover, although with high uncertainties, most climate models used for the region recognize a growing uncertainty in the onset of the rainy season, which demands urgent adaptation measures. Early-season drought limits crops germination, and hence growth, and yield during rainfed depending production as is common now in Mali, West Africa. Crops germination and establishment could be improved by using seed priming, a process that dry seeds take up water to initiate the primary stages of germination, but the amount of water added is not enough for completing germination. The effects of hydro-priming (distilled, tap, rain, river and well water) were evaluated for three priming durations (4, 8 and 12 hour) in 2014 and 2015. Monitored were seed germination and seedling development of nine sorghum genotypes. Preliminary results showed that hydro-priming significantly improved germination rate, germination speed, number of seminal root, rate of survival and seedling vigour index, compared to non-primed seed treatments. However, seedling length, root length, shoot length and seedling dry weight did not differ significantly. Four out of the nine genotypes evaluated were attributed good seed quality and good response to hydro-priming. The priming with different sources of water resulted in higher seed germination (90%) and seedling development with well and river water, compared to the others. Seed germination rate, uniformity and speed were also enhanced by hydro-priming. It is argued that hydro-priming is a simple but effective method for improving seed germination and seedling development of sorghum. In addition hydro-priming is a safe, simple and inexpensive method to enhance germination. The most promising genotypes have consequently been included in consequent pot

  6. Release of Paramecium immobilization antigen to the non-nutrient medium.

    Science.gov (United States)

    Wyroba, E

    1980-01-01

    The instability of Paramecium aurelia surface components has been shown: after 60 min incubation of dense cell suspension ((1-2 . 10(6) cells per ml) in Tris-Ca buffer at 4 degrees C or 23 degrees C the surface coat was partially stripped off and the proteins were released to the medium. The electrophoretic analysis of the released proteins shows one major band of mol. wt. 280,000--300,000 and some minor bands. The major released protein is the immobilization antigen as proved using immunodiffusion test and antibody precipitation technique.

  7. Nutrient and nonnutrient components of legumes, and its chemopreventive activity: a review.

    Science.gov (United States)

    Sánchez-Chino, Xariss; Jiménez-Martínez, Cristian; Dávila-Ortiz, Gloria; Álvarez-González, Isela; Madrigal-Bujaidar, Eduardo

    2015-01-01

    Legumes in combination with other products are the staple food for a large part of the world population, especially the low-income fragment, because their seeds provide valuable amounts of carbohydrates, fiber, and proteins, and have an important composition of essential amino acids, the sulphured amino acids being the limiting ones. Furthermore, legumes also have nonnutritional compounds that may decrease the absorption of nutrients or produce toxic effects; however, it has been reported that depending on the dose, these nonnutritional compounds also have different bioactivities as antioxidant, hypolipidemic, hypoglycemic, and anticarcinogenic agents, which have been proven in scientific studies. It has been observed that in countries with a high consumption of legumes, the incidence of colorectal cancer is lower. Some studies have shown that legume seeds are an alternative chemopreventive therapy against various cancers especially colon; this was verified in various animal models of induced by azoxymethane, a colon specific carcinogenic compound, in which a diet was supplemented with different concentrations of beans, lentils, chickpeas, or soybeans, mostly. These studies have proven the anticancer activity of legumes in early stages of carcinogenesis. Therefore, it is important to review the information available to elucidate the chemopreventive mechanisms of action of legume compounds.

  8. Seedling survival of Handroanthus impetiginosus (Mart ex DC) Mattos in a semi-arid environment through modified germination speed and post-germination desiccation tolerance.

    Science.gov (United States)

    Martins, J R; Edvaldo, A A S; Alvarenga, A A; Rodrigues, A C; Ribeiro, D E; Toorop, P E

    2015-11-01

    Uniform rapid seed germination generally forms a great risk for the plant population if subsequent intermittent precipitation causes desiccation and seedling death. Handroanthus impetiginosus can be found commonly in a wide range of biomes within Brazil including those that are semi-arid. Germination and early growth was studied to understand how germinated seeds survive under these stringent conditions. Accessions were sampled from four seasonally dry biomes in Brazil. Precipitation at the start of the rainy season in the Caatinga, a semi-arid biome, is less predictable and the number of successive dry days per dry interval in the first four months of the rainy season was higher than in the other studied biomes. Plants from the Caatinga produced thicker seeds and this trait concurred with slow germination and stronger osmotic inhibition of germination across the accessions, forming a stress avoidance mechanism in the Caatinga. Post-germination desiccation tolerance was high in the Caatinga accession, could be re-induced in accessions from biomes with more regular precipitation (Cerrado and transition zone), but remained poor in the Cerradão accession; thus forming a stress tolerance mechanism. Production of adventitious roots ascertained survival of all tested individuals from all four locations, even if protruded radicles did not survive desiccation, forming an additional stress tolerance mechanism. A sequence of stress avoidance and stress tolerance mechanisms in seeds and germinated seeds was associated with precipitation patterns in different biomes. These mechanisms purportedly allow rapid seedling establishment when conditions are suitable and enable survival of the young seedling when conditions are adverse.

  9. Seedling survival of Handroanthus impetiginosus (Mart ex DC Mattos in a semi-arid environment through modified germination speed and post-germination desiccation tolerance

    Directory of Open Access Journals (Sweden)

    J. R. Martins

    Full Text Available Abstract Uniform rapid seed germination generally forms a great risk for the plant population if subsequent intermittent precipitation causes desiccation and seedling death. Handroanthus impetiginosus can be found commonly in a wide range of biomes within Brazil including those that are semi-arid. Germination and early growth was studied to understand how germinated seeds survive under these stringent conditions. Accessions were sampled from four seasonally dry biomes in Brazil. Precipitation at the start of the rainy season in the Caatinga, a semi-arid biome, is less predictable and the number of successive dry days per dry interval in the first four months of the rainy season was higher than in the other studied biomes. Plants from the Caatinga produced thicker seeds and this trait concurred with slow germination and stronger osmotic inhibition of germination across the accessions, forming a stress avoidance mechanism in the Caatinga. Post-germination desiccation tolerance was high in the Caatinga accession, could be re-induced in accessions from biomes with more regular precipitation (Cerrado and transition zone, but remained poor in the Cerradão accession; thus forming a stress tolerance mechanism. Production of adventitious roots ascertained survival of all tested individuals from all four locations, even if protruded radicles did not survive desiccation, forming an additional stress tolerance mechanism. A sequence of stress avoidance and stress tolerance mechanisms in seeds and germinated seeds was associated with precipitation patterns in different biomes. These mechanisms purportedly allow rapid seedling establishment when conditions are suitable and enable survival of the young seedling when conditions are adverse.

  10. Transcriptional analysis of temporal gene expression in germinating Clostridium difficile 630 endospores.

    Directory of Open Access Journals (Sweden)

    Marcin Dembek

    Full Text Available Clostridium difficile is the leading cause of hospital acquired diarrhoea in industrialised countries. Under conditions that are not favourable for growth, the pathogen produces metabolically dormant endospores via asymmetric cell division. These are extremely resistant to both chemical and physical stress and provide the mechanism by which C. difficile can evade the potentially fatal consequences of exposure to heat, oxygen, alcohol, and certain disinfectants. Spores are the primary infective agent and must germinate to allow for vegetative cell growth and toxin production. While spore germination in Bacillus is well understood, little is known about C. difficile germination and outgrowth. Here we use genome-wide transcriptional analysis to elucidate the temporal gene expression patterns in C. difficile 630 endospore germination. We have optimized methods for large scale production and purification of spores. The germination characteristics of purified spores have been characterized and RNA extraction protocols have been optimized. Gene expression was highly dynamic during germination and outgrowth, and was found to involve a large number of genes. Using this genome-wide, microarray approach we have identified 511 genes that are significantly up- or down-regulated during C. difficile germination (p≤0.01. A number of functional groups of genes appeared to be co-regulated. These included transport, protein synthesis and secretion, motility and chemotaxis as well as cell wall biogenesis. These data give insight into how C. difficile re-establishes its metabolism, re-builds the basic structures of the vegetative cell and resumes growth.

  11. Germination and growth of Magonia pubescens A. ST.-HIL seedlings

    Directory of Open Access Journals (Sweden)

    Ani Cátia Giotto

    2009-03-01

    Full Text Available This study aimed to analyze the germination, growth and development of Magonia pubescens A. St.-Hil. (tinguí ortimbó, a typical species of the deciduous forest. The germination of seeds of four matrices was evaluated at different treatments: directsowing in greenhouse (50% of shade, direct sowing under full sunlight and moistened paper at laboratory condition and underfluorescent light with photoperiod of 12 hours in ambient temperature. The germinated seeds under laboratory conditions weretransplanted to polyethylene bags with soil under full sunlight and 50% of shade. The variables evaluated were: time of the first andlast germination, germinability; average time and the rates of speed of germination index. In addition there were evaluated the seedlingheight, stem base diameter, number of leaf and leaflets were monitored at 30, 60, 90 and 120 days. The species presented highgerminability at laboratory conditions (G> 90% and under full sunlight (96%>G>56%, however, the germinability in 50% shadepresented inferior result (G0.05. The leaf and leaflets number varied among treatments, with highest average for seedling under full sunlight. Suggesting thatMagonia pubescens A. St.-Hil. is a useful species for rehabilitation of degraded areas.

  12. Germination biology of Hibiscus tridactylites in Australia and the implications for weed management

    Science.gov (United States)

    Chauhan, Bhagirath Singh

    2016-05-01

    Hibiscus tridactylites is a problematic broadleaf weed in many crops in Australia; however, very limited information is available on seed germination biology of Australian populations. Experiments were conducted to evaluate the effect of environmental factors on germination and emergence of H. tridactylites. Germination was stimulated by seed scarification, suggesting the inhibition of germination in this species is mainly due to the hard seed coat. Germination was not affected by light conditions, suggesting that seeds of this species are not photoblastic. Germination was higher at alternating day/night temperatures of 30/20 °C (74%) and 35/25 °C (69%) than at 25/15 °C (63%). Moderate salinity and water stress did not inhibit germination of H. tridactylites. Seedling emergence of H. tridactylites was highest (57%) for the seeds buried at a 2 cm depth in the soil; 18% of seedlings emerged from seeds buried at 8 cm but no seedlings emerged below this depth. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence could serve an important tool for managing H. tridactylites.

  13. Abiotic Limits for Germination of Sugarcane Seed in Relation to Environmental Spread.

    Science.gov (United States)

    Pierre, J S; Rae, A L; Bonnett, G D

    2014-01-01

    Sugarcane is a vegetatively propagated crop and hence the production of seed and its fate in the environment has not been studied. The recent development of genetically modified sugarcane, with the aim of commercial production, requires a research effort to understand sugarcane reproductive biology. This study contributes to this understanding by defining the abiotic limits for sugarcane seed germination. Using seed from multiple genetic crosses, germination was measured under different light regimes (light and dark), temperatures (from 18 °C to 42 °C) and water potentials (from 0 MPa to -1 MPa); cardinal temperatures and base water potential of germination were estimated based on the rates of germination. We found that sugarcane seed could germinate over a broad range of temperatures (from 11 °C to 42 °C) with optima ranging from 27 °C to 36 °C depending on source of seed. Water potentials below -0.5 MPa halved the proportion of seed that germinated. By comparing these limits to the environmental conditions in areas where sugarcane grows and has the potential to produce seed, water, but not temperature, will be the main limiting factor for germination. This new information can be taken into account when evaluating any risk of weediness during the assessment of GM sugarcane.

  14. Beyond gibberellins and abscisic acid: how ethylene and jasmonates control seed germination.

    Science.gov (United States)

    Linkies, Ada; Leubner-Metzger, Gerhard

    2012-02-01

    Appropriate responses of seeds and fruits to environmental factors are key traits that control the establishment of a species in a particular ecosystem. Adaptation of germination to abiotic stresses and changing environmental conditions is decisive for fitness and survival of a species. Two opposing forces provide the basic physiological mechanism for the control of seed germination: the increasing growth potential of the embryo and the restraint weakening of the various covering layers (seed envelopes), including the endosperm which is present to a various extent in the mature seeds of most angiosperms. Gibberellins (GA), abscisic acid (ABA) and ethylene signaling and metabolism mediate environmental cues and in turn influence developmental processes like seed germination. Cross-species work has demonstrated that GA, ABA and ethylene interact during the regulation of endosperm weakening, which is at least partly based on evolutionarily conserved mechanisms. We summarize the recent progress made in unraveling how ethylene promotes germination and acts as an antagonist of ABA. Far less is known about jasmonates in seeds for which we summarize the current knowledge about their role in seeds. While it seems very clear that jasmonates inhibit germination, the results obtained so far are partly contradictory and depend on future research to reach final conclusions on the mode of jasmonate action during seed germination. Understanding the mechanisms underlying the control of seed germination and its hormonal regulation is not only of academic interest, but is also the ultimate basis for further improving crop establishment and yield, and is therefore of common importance.

  15. Effects of the hydrogen potential and fungicide treatment on Pitaya seed germination

    Directory of Open Access Journals (Sweden)

    Thiago Alberto Ortiz

    2014-11-01

    Full Text Available The objective of the present study was to evaluate pitaya seed germination under different hydrogen potentials, with or without fungicide treatment. A completely randomized design was employed under a 3 x 13 x 2 factorial scheme, corresponding to three pitaya species (white pitaya, pitaya hybrid I, pitaya hybrid II, thirteen hydrogen potentials (3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, and 9.0 and two fungicide conditions (presence and absence, with four replications. The percentage of germination, germination speed index and mean germination time were evaluated. The data were subjected to ANOVA, and the means were compared using the Scott-Knott test (p < 0.05. The pH influenced the germination speed index in white pitaya. The mean germination time was affected by the pH levels for white pitaya and pitaya hybrid II. The fungicide did not increase the germination percentage in the evaluated species.

  16. Seed germination and seedling growth of two Pseudobombax species (Malvaceae) with contrasting habitats from Brazilian Cerrado.

    Science.gov (United States)

    Mendes-Rodrigues, Clesnan; Oliveira, Paulo Eugênio; Ranal, Marli Aparecida

    2011-12-01

    Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designed and included four replicates with 25 seeds per species; seeds were randomly distributed in the germination chamber. To evaluate initial seedling growth, seedlings height was measured up to 67 days after seedling emergence; besides, some of these seedlings were grown for biomass evaluation during nine months. Results showed that seeds of the two species had the same germinability (near 100%) and mean germination time (ca. 12 days). However, P. longiflorum showed a more spread seed germination through time, with higher values of coefficient of variation in germination time and uncertainty index; and lower values of synchronization than P. tomentosum. The two species showed basically the same growth pattern, but lower values for height of apical meristem, diameter of underground structures (mostly roots), dry mass of shoots, underground structure and total mass of seedlings in P. tomentosum were obtained, compared to P. longiflorum. Both species allocated more dry mass to underground structures in detriment of shoot. This probably allows resprouting behavior which prevents hydric stress and detrimental fire action typical of the open Cerrado areas.

  17. Survival and germination of Mediterranean grassland species after simulated sheep ingestion: ecological correlates with seed traits

    Science.gov (United States)

    Peco, B.; Lopez-Merino, L.; Alvir, M.

    2006-09-01

    Large amounts of viable seeds from Mediterranean grassland species have been found in herbivore dung; however which species produce seeds that can survive and germinate after ingestion by herbivores is still not well understood. This paper evaluates the importance of seed size, shape and coat impermeability in the endozoochorous dispersal process of 20 abundant species from central Iberian rangelands. Seed survival, germination percentages and germination speed were analysed in controlled experiments on the chewing and gut passage process by inserting seeds in the rumen of fistulated sheep, followed by simulated acid-pepsin digestion. Higher germination percentages in the control than the simulated sheep ingestion treatment were found in 75% of seeds. All species showed lower survival following the treatment, two species had a higher germination speed and five had a lower rate. Large-seeded species generally had higher survival percentages than small-seeded species. Species with impermeable seed coats had higher germination percentages following treatment although no significant differences were noted for either seed survival or germination speed.

  18. Influence of Temperature and Salinity on Germination of Eelgrass (Zostera marina L.) Seeds

    Institute of Scientific and Technical Information of China (English)

    PAN Jinhua; YANG Guanpin; JIANG Xin; LI Xiaojie; CONG Yizhou; ZHANG Zhuangzhi; LI Zhiling; ZHOU Weili; HAN Houwei; LUO Shiju

    2011-01-01

    Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has been widely accepted as the most potentially useful method for seagrass restoration over large areas. We examined the influence of key environmental factors on seed germination to help promote eelgrass bed restoration. Under anoxic conditions, the influence of temperature and salinity on the germination rate of eelgrass (Zostera marina L.) seeds was examined at different combinations of four temperatures (4, 9, 14, and 24℃) and nine salinities (5 to 45, increment of 5). The effect of significant interaction of temperature and salinity on germination rate was observed (ANOVA)(P<0.001). The highest germination rate (83.3 ±3.5)% was reached in 8 weeks at 14℃ and salinity 5. Higher temperature significantly increased the germination rate at salinity 5 (P<0.001) during the whole observation period except for 24℃,while lower salinity significantly increased the germination rate at 14℃ (P<0.001). Although significant interaction was found between temperature and salinity (P<0.001), the influence of salinity was stronger than that of temperature for the germination of eelgrass seeds. These results provide useful information for the propagation of artificial seedlings for seagrass restoration in China.

  19. Seed germination of montane forest species in response to ash, smoke and heat shock in Mexico

    Science.gov (United States)

    Zuloaga-Aguilar, Susana; Briones, Oscar; Orozco-Segovia, Alma

    2011-05-01

    In many fire-prone ecosystems, seed germination is triggered by heat shock, smoke, ash and charred wood. However, few studies concerning the effect of these fire products on the germination of tropical and subtropical species exist. We assessed the effect of fire products and their interactions on seed germination in 12 species that frequently grow in burned areas of pine-oak and mixed forest in a mountainous subtropical area. Each species was exposed to a predetermined treatment of heat shock, which was optimised in accordance with a previous study. For smoke treatments, seeds were immersed in smoke water, whereas for ash treatments, 1.5 g of ash was added to the incubation medium. Germination increased in 92% of the species in response to the products of fire. Both the smoke water and the ash treatments promoted germination in four species that had permeable seed covers and physiological dormancy. Six species with physical dormancy required both heat shock and smoke water or ash to break dormancy. Our results indicate that seed germination response to fire products depends on the species and/or dormancy type. The germination response to the fire products varied between species; therefore, fire products may influence the species composition in post-fire regeneration.

  20. Pollen germination of the walnut cultivar ‛Geisenheim 286’ on different culture media

    Directory of Open Access Journals (Sweden)

    Janković Dragan M.

    2014-01-01

    Full Text Available Pollen of the walnut cultivar ‛Geisenheim 286(27.8% when the germination medium contained 0.8% of agar, 15% of sucrose, 600 ppm of ’ was cultured on germination media containing all possible combinations of sucrose (10, 15 and 20%; agar (0.6 and 0.8%; boric acid (0, 300 and 600 ppm and calcium chloride (0, 50 and 100 ppm. A total of 54 different combinations of germination media were tested in an attempt to establish a suitable culture in vitro pollen germinability The interactions of the concentrations of agar and calcium chloride, boric acid and sucrose, calcium chloride and sucrose, as well as those of boric acid, calcium chloride and sucrose were significant. Pollen germination was maximized media for studying of the walnut. Significant differences in pollen germination were observed in response to changing concentrations of sucrose, boric acid and calcium chloride, but germination was not affected by changes in agar concentration. boric acid and 50 ppm of calcium chloride.

  1. The Arabidopsis CROWDED NUCLEI genes regulate seed germination by modulating degradation of ABI5 protein

    Institute of Scientific and Technical Information of China (English)

    Wenming Zhao; Chunmei Guan; Jian Feng; Yan Liang; Ni Zhan; Jianru Zuo; Bo Ren

    2016-01-01

    In Arabidopsis, the phytohormone abscisic acid (ABA) plays a vital role in inhibiting seed germination and in post-germination seedling establishment. In the ABA signaling pathway, ABI5, a basic Leu zipper transcription factor, has important functions in the regulation of seed germination. ABI5 protein localizes in nuclear bodies, along with AFP, COP1, and SIZ1, and was degraded through the 26S proteasome pathway. However, the mechanisms of ABI5 nuclear body formation and ABI5 protein degradation remain obscure. In this study, we found that the Arabidopsis CROWDED NUCLEI (CRWN) proteins, predicted nuclear matrix proteins essential for maintenance of nuclear morphology, also participate in ABA-control ed seed germination by regulating the degradation of ABI5 protein. During seed germination, the crwn mutants are hypersensitive to ABA and have higher levels of ABI5 protein compared to wild type. Genetic analysis suggested that CRWNs act upstream of ABI5. The observation that CRWN3 colocalizes with ABI5 in nuclear bodies indicates that CRWNs might participate in ABI5 protein degrada-tion in nuclear bodies. Moreover, we revealed that the extreme C-terminal of CRWN3 protein is necessary for its function in the response to ABA in germination. Our results suggested important roles of CRWNs in ABI5 nuclear body organization and ABI5 protein degradation during seed germination.

  2. Proteomic Dissection of Seed Germination and Seedling Establishment in Brassica napus.

    Science.gov (United States)

    Gu, Jianwei; Chao, Hongbo; Gan, Lu; Guo, Liangxing; Zhang, Kai; Li, Yonghong; Wang, Hao; Raboanatahiry, Nadia; Li, Maoteng

    2016-01-01

    The success of seed germination and establishment of a normal seedling are key determinants of plant species propagation. At present, only a few studies have focused on the genetic control of seed germination by using a proteomic approach in Brassica napus. In the present study, the protein expression pattern of seed germination was investigated using differential fluorescence two-dimensional gel electrophoresis in B. napus. One hundred and thirteen differentially expressed proteins (DEPs) that were mainly involved in storage (23.4%), energy metabolism (18.9%), protein metabolism (16.2%), defense/disease (12.6%), seed maturation (11.7%), carbohydrate metabolism (4.5%), lipid metabolism (4.5%), amino acids metabolism (3.6%), cell growth/division (3.6%), and some unclear functions (2.7%) were observed by proteomic analysis. Seventeen genes corresponding to 11 DEPs were identified within or near the associated linkage disequilibrium regions related to seed germination and vigor quantitative traits reported in B. napus in previous studies. The expression pattern of proteins showed that heterotrophic metabolism could be activated in the process of seed germination and that the onset of defense mechanisms might start during seed germination. These findings will help generate a more in-depth understanding of the mobilization of seed storage reserves and regulation mechanisms of the germination process in B. napus.

  3. SUBSTRATES AND TEMPERATURES FOR THE GERMINATION OF SEEDS OF Senegalia tenuifolia (L. BRITTON & ROSE

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    ALCIMONE MARIA SILVA ARAÚJO

    2016-01-01

    Full Text Available The Rules for Seed Analysis and the Instructions for Seed Analysis of Forest Species have no recommendations for conducting the S. tenuifolia germination test. Therefore, the aim of the present study was to evaluate different temperatures and substrates to perform the germination test of S. tenuifolia seeds. The experimental design was completely randomized in a factorial 4 × 3 design and consisted of four substrates (paper roll; on paper; on sand and on vermiculite and three temperatures (25, 30 and 35 °C, with four replicates of 25 seeds. The percentage of normal seedlings, the germination speed index, the shoot length, root length and dry mass of seedlings were evaluated. The Tukey test was used at 5% probability. There was a significant interaction between the temperatures and substrates tested for all variables, indicating that there is at least one ideal combination of the two factors that can increase the germination of seeds. The germination and vigor of S. tenuifolia seeds are influenced by the temperature and by the substrate used in the germination test. The combination of the paper roll substrates with a temperature of 25 and 30 °C was suitable for the germination of S. tenuifolia seeds.

  4. Salinity Effects on Germination Properties ofPurslane (Portulaca oleracea L.

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    m Kafi

    2011-02-01

    Full Text Available Abstract In order to study seed germination and seedling growth responses of purslane to different levels of salinity, an experiment was conducted in a completely randomized desgin with six levels of salinity (0, 7, 14, 21, 28 and 35 dS/m using NaCl and five replications. Persentage and rate of germination, length and dry weight of radicle and plumule were measured, and ratio radicle to plumule length, mean germination time and seedling vigor index were calculated. The results showed that up to 28 dS/m salinity did not impose any significant different in germination percentage compared with control, but in 35 dS/m salinity it decreased to 19%. germination rate did not show any significant different up to 14 dS/m in comparison with control but beyond this level it significantly decreased with increasing salt stress. Mean germination time up to 21 dS/m did not have significant different in comparison with control, but increased with increasing salinity significantly. Length, fresh and dry weight of radicle and plumule, and seedling vigor index significantly decreased by increasing salinity. Ratio of radicle to plumule length decreased with increasing salt concentration, but there were not significant different among salt levels. According to the results, the germination stage of purslane is remarkably resistant to elevated levels of salinity and it seems that by exerting proper management in farms, it could be established in saline environments. Keywords: Plumule, Radicle, Seedlings of purslane

  5. Salicylic acid promotes seed germination under high salinity by modulating antioxidant activity in Arabidopsis.

    Science.gov (United States)

    Lee, Sangmin; Kim, Sang-Gyu; Park, Chung-Mo

    2010-10-01

    • Findings regarding the role of salicylic acid (SA) in seed germination are somewhat variable, depending on the plant genotypes and experimental conditions used, and thus the molecular mechanisms underlying SA regulation of germination are still unclear. Here, we report that physiological concentrations of SA promote germination under high salinity by modulating antioxidant activity in Arabidopsis. • Germination of SA induction deficient 2 (sid2) seeds was hypersensitive to high salinity. While the inhibitory effect of high salinity was exaggerated in the presence of higher concentrations of SA (> 100 μM), it was significantly reduced in the presence of lower concentrations of SA (salinity, the endogenous contents of H(2) O(2) were elevated in wild-type and sid2 seeds but reduced to original concentrations after treatment with 1 μM SA. • Germination of NahG transgenic plants was influenced to a lesser degree by high salinity (NahG is a bacterial gene encoding salicylate hydroxylase that converts salicylic acid to catechol). We found that catechol, an SA degradation product accumulated in the transgenic plants, acts as an antioxidant that compromises the inhibitory effects of high salinity. • Our observations indicate that, although SA is not essential for germination under normal growth conditions, it plays a promotive role in seed germination under high salinity by reducing oxidative damage.

  6. Effect of salinity on Arabidopsis thaliana seed germination and acid phosphatase activity

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    Nasri Nawel

    2016-01-01

    Full Text Available The salt tolerance of four accessions of Arabidopsis thaliana (COL (Columbia, NOK2, N1438 and N1380 was evaluated during germination by the capacity of seeds to germinate in the presence of 50 mM NaCl and to maintain adequate acid phosphatase activity. Our results show that saline conditions reduced the final germination percentage, speed of germination and delayed the germination processes of accessions NOK2, N1438 and N1380. In contrast, 100% of germination was found in COL under salt-stress conditions. In the presence of NaCl 50 mM, acid phosphatase activity increased in the first 24 h, the activity reaching the control level in germinating seeds of COL, but in the three other accessions NOK2, N1438 and N1380, acid phosphatase activity diminished under salt stress. These findings suggest that changes in the phosphatase enzymes might play an important role in the acclimation of COL seeds to the changing environmental conditions.

  7. Proteomic dissection of seed germination and seedling establishment in Brassica napus

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    Jianwei Gu

    2016-10-01

    Full Text Available The success of seed germination and the establishment of a normal seedling are key determinants of plant species propagation. At present, only few studies have focused on the genetic control of the seed germination by proteomic approach in Brassica napus. In the present study, the protein expression pattern of seed germination was investigated using differential fluorescence two-dimensional gel electrophoresis (2-D DIGE in B. napus. One hundred thirteen differentially expressed proteins (DEPs, which were mainly involved in storage proteins (23.4%, energy metabolism (18.9%, protein metabolism (16.2%, defense/disease (12.6%, seed maturation (11.7%, carbohydrate metabolism (4.5%, lipid metabolism (4.5%, amino acids metabolism (3.6%, cell growth/division (3.6%, and some unclear proteins (2.7% were observed by proteomic analysis. Seventeen genes corresponding to 11 DEPs were identified within or near the associated linkage disequilibrium regions related to seed germination and vigor quantitative traits reported in B. napus in previous studies. The expression pattern of proteins showed the heterotrophic metabolism could be activated in the process of seed germination and the onset of defense system might start during seed germination. These findings will help us more in-depth understanding of the mobilization of seed storage reserves and regulation mechanisms of germination process in B. napus.

  8. Modelling Soil Water Retention for Weed Seed Germination Sensitivity to Water Potential

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    W. John Bullied

    2012-01-01

    Full Text Available Soil water retention is important for the study of water availability to germinating weed seeds. Six soil water retention models (Campbell, Brooks-Corey, four- and five-parameter van Genuchten, Tani, and Russo with residual soil water parameter derivations were evaluated to describe water retention for weed seed germination at minimum threshold soil water potential for three hillslope positions. The Campbell, Brooks-Corey, and four-parameter van Genuchten model with modified or estimated forms of the residual parameter had superior but similar data fit. The Campbell model underestimated water retention at a potential less than −0.5 MPa for the upper hillslope that could result in underestimating seed germination. The Tani and Russo models overestimated water retention at a potential less than −0.1 MPa for all hillslope positions. Model selection and residual parameter specification are important for weed seed germination by representing water retention at the level of minimum threshold water potential for germination. Weed seed germination models driven by the hydrothermal soil environment rely on the best-fitting soil water retention model to produce dynamic predictions of seed germination.

  9. Germination of Medicago sativa is inhibited by soluble compounds in cement dust.

    Science.gov (United States)

    Lafragüeta, Cristina; García-Criado, Balbino; Arranz, Angel; Vázquez-de-Aldana, Beatriz R

    2014-01-01

    Deposition of cement dust on soils and plant surfaces is known to affect plant growth and the species composition of plant communities, but little is known about its effects (and those of its pH and constituents) on germination. Therefore, the aim of this study was to assess the toxicity of an aqueous cement extract, constituents of the extract and pH on the germination of seeds of a selected species, Medicago sativa. First, the effects of the extract were tested in assays with concentrations and exposure durations ranging from 0 to 1.0 g/mL and 4 to 96 h, respectively. At 0.8 g/mL, the extract strongly inhibited germination; a 4-h exposure reduced the germination rate, from 77 ± 1.8 to 50 ± 2.6% (mean ± SE), while 8-h exposure completely inhibited it. Further, treatment at this concentration killed the non-germinating seeds, thus the inhibition was due to toxic effects. Neither the pH of the extract nor the concentration of its main soluble elements separately (K, Ca, S, Na, or Cr) caused the toxicity since germination rates were not significantly reduced when these variables were tested individually. However, a mixture of the elements in solution reduced germination rates, suggesting that they have adverse synergistic effects.

  10. Prevention of Preharvest Sprouting through Hormone Engineering and Germination Recovery by Chemical Biology.

    Science.gov (United States)

    Nonogaki, Mariko; Nonogaki, Hiroyuki

    2017-01-01

    Vivipary, germination of seeds on the maternal plant, is observed in nature and provides ecological advantages in certain wild species, such as mangroves. However, precocious seed germination in agricultural species, such as preharvest sprouting (PHS) in cereals, is a serious issue for food security. PHS reduces grain quality and causes economical losses to farmers. PHS can be prevented by translating the basic knowledge of hormone biology in seeds into technologies. Biosynthesis of abscisic acid (ABA), which is an essential hormone for seed dormancy, can be engineered to enhance dormancy and prevent PHS. Enhancing nine-cis-epoxycarotenoid dioxygenase (NCED), a rate-limiting enzyme of ABA biosynthesis, through a chemically induced gene expression system, has successfully been used to suppress germination of Arabidopsis seeds. The more advanced system NCED positive-feedback system, which amplifies ABA biosynthesis in a seed-specific manner without chemical induction, has also been developed. The proofs of concept established in the model species are now ready to be applied to crops. A potential problem is recovery of germination from hyperdormant crop grains. Hyperdormancy induced by the NCED systems can be reversed by inducing counteracting genes, such as NCED RNA interference or gibberellin (GA) biosynthesis genes. Alternatively, seed sensitivity to ABA can be modified to rescue germination using the knowledge of chemical biology. ABA antagonists, which were developed recently, have great potential to recover germination from the hyperdormant seeds. Combination of the dormancy-imposing and -releasing approaches will establish a comprehensive technology for PHS prevention and germination recovery.

  11. Can Bulk and Nanosized Titanium Dioxide Particles Improve Seed Germination Features of Wheatgrass (Agropyron desertorum

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    Reyhaneh AZIMI

    2013-08-01

    Full Text Available The goal of this study was to evaluate concentrations of nanosized TiO2 at 0, 5, 20, 40, 60 and 80 mg L-1 with bulk TiO2 for possible stimulatory effects on wheatgrass seed germination and early growth stage. After 14 days of seed incubation, germination percentage improved by 9% following exposure to 5 ppm nanosized TiO2 treatment comparing to control. Similar positive effects occurred in terms of germination value and mean daily germination. Application of bulk TiO2 particles in 80 ppm concentration greatly decreased the majority of studied traits. Therefore phytotoxicity effect observed on wheatgrass seedling by application of bulk TiO2 particles in 80 ppm concentration. Exposure of wheatgrass seeds to 5 ppm nanosized TiO2 and bulk and nanosized TiO2 at 60 ppm obtained the lowest mean germination time but higher concentrations did not improve mean germination time. In general, there was a positive response by wheatgrass seed to some concentrations of nanosized TiO2. Usage of nanoparicles in order to improve germination and establishment of range plant in adverse environments similar to rangeland could be possible.

  12. The effect of temperature on pollen germination and pollen tube growth of sour cherry cultivars

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    Milatović Dragan P.

    2014-01-01

    Full Text Available The study was carried out to determine the effect of three different temperatures (5, 15 and 25°C on in vitro pollen germination and pollen tube growth of five sour cherry cultivars: ‘Heimanns Konservenweichsel’, ‘Kelleriis 14’, ‘Oblačinska’, ‘Rexelle’ and ‘Šumadinka’. Pollen germination a % agar % Temperature significantly affected pollen germination. High germination rates (50-70% were obtained at both 15°C and 25°C. Satisfactory germination rates (42-51% were also obtained at 5°C in some cultivars (‘Rexelle’, ‘Šumadinka’ and ‘Heimanns Konservenweichsel’. The influence of temperature on the pollen tube growth was more prominent. The length of pollen tubes was three to six times higher at 15°C and 25°C in comparison with 5°C. This has led to the conclusion that the temperature of 5°C, although it could be adequate for pollen germination, is not high enough for optimal pollen tube growth. was determined by germinating pollen grains in culture medium containing 0.7agar-and 15sucrose. [Projekat Ministarstva nauke Republike Srbije, br. TR-31063

  13. Hydrothermal time models for conidial germination and mycelial growth of the seed pathogen Pyrenophora semeniperda.

    Science.gov (United States)

    Barth, Connor W; Meyer, Susan E; Beckstead, Julie; Allen, Phil S

    2015-08-01

    Population-based threshold models using hydrothermal time (HTT) have been widely used to model seed germination. We used HTT to model conidial germination and mycelial growth for the seed pathogen Pyrenophora semeniperda in a novel approach to understanding its interactions with host seeds. Germination time courses and mycelial growth rates for P.semeniperda were measured on PDA amended to achieve a series of five water potentials (ca. 0 to -6 MPa) at six constant temperatures (5-30 °C). Conidial germination was described with alternative population-based models using constant or variable base and maximum temperature and water potential parameters. Mycelial growth was modeled as a continuous, linear process with constant base temperature and base water potential. Models based on HTT showed reasonable fit to germination and growth rate data sets. The best-fit conidial germination model (R(2) = 0.859) was based on variable base and maximum temperature as a function of water potential. The good fit of the linear mycelial growth model (R(2) = 0.916) demonstrated the utility of HTT for modeling continuous as well as population-based processes. HTT modeling may be a useful approach to the quantification of germination and growth processes in a wide range of filamentous fungi. Published by Elsevier Ltd.

  14. Effect of calcium and light on the germination of Urochondra setulosa under different salts

    Institute of Scientific and Technical Information of China (English)

    SHAIKH Faiza; GUL Bilquees; LI Wei-qiang; LIU Xiao-jing; KHAN M. Ajmal

    2007-01-01

    Urochondra setulosa (Trin.) C.E. Hubbard is a coastal halophytic grass thriving on the coastal dunes along the Pakistani seashore. This grass could be useful in coastal sand dune stabilization using seawater irrigation. The purpose of this investigation was to test the hypothesis that Ca2+ (0.0, 2.5, 5.0, 10.0 and 50.0 mmol/L) alleviates the adverse effects of KCl,MgSO4, NaCl and Na2SO4 at 0, 200, 400, 600, 800 and 1000 mmol/L on the germination of Urochondra setulosa. Seed germination was inhibited with increase in salt concentration with few seeds germinated at and above 400 mmol/L concentration. No seed germinated in any of the KCl treatments. Inclusion of CaCl2 substantially alleviated the inhibitory effects of all salts. Germination was higher under photoperiod in comparison to those seeds germinated under complete darkness, Among the CaCl2 concentrations used, 10 mmol/L was most effective in alleviating salinity effects and allowing few seeds to germinate at 1000 mmol/L KCl, MgSO4, NaCl and Na2SO4 solution.

  15. Enhanced tocopherol levels during early germination events in Chamaerops humilis var. humilis seeds.

    Science.gov (United States)

    Siles, Laura; Alegre, Leonor; Tijero, Verónica; Munné-Bosch, Sergi

    2015-10-01

    Most angiosperms accumulate vitamin E in the form of tocopherols in seeds, exerting a protective antioxidant role. However, several palm trees principally accumulate tocotrienols, rather than tocopherols, in seeds, as it occurs in other monocots. To unravel the protective role of either tocopherols or tocotrienols against lipid peroxidation during seed germination in Chamaerops humilis var. humilis; seed viability, natural and induced germination capacity, seed water content, malondialdehyde levels (as an indicator of the extent of lipid peroxidation) and vitamin E levels (including both tocopherols and tocotrienols) were examined at various germination phases in a simulated, natural seed bank. At the very early stages of germination (operculum removal), malondialdehyde levels increased 2.8-fold, to decrease later up to 74%, thus indicating a transient lipid peroxidation at early stages of germination. Tocopherol levels were absent in quiescent seeds and did not increase during operculum removal, but increased later presumably dampening malondialdehyde accumulation. Thereafter, tocopherols continued increasing, while lipid peroxidation levels decreased. By contrast, tocotrienols levels remained constant or even decreased as germination progressed, showing no correlation with lipid peroxidation levels. We hypothesize that despite their high tocotrienol content, seeds synthesize tocopherols during germination to protect lipids from peroxidation events.

  16. At-line determining spore germination of Penicillium chrysogenum bioprocesses in complex media.

    Science.gov (United States)

    Ehgartner, Daniela; Fricke, Jens; Schröder, Andreas; Herwig, Christoph

    2016-10-01

    Spore inoculum quality in filamentous bioprocesses is a critical parameter associated with viable spore concentration (1) and spore germination (2). It influences pellet morphology and, consequently, process performance. The state-of-the-art method to measure viable spore concentration is tedious, associated with significant inherent bias, and not applicable in real-time. Therefore, it is not usable as process analytical technology (PAT). Spore germination has so far been monitored using image analysis, which is hampered by complex medium background often observed in filamentous bioprocesses. The method presented here is based on the combination of viability staining and large-particle flow cytometry which enables measurements in real-time and hence aims to be applicable as a PAT tool. It is compatible with the complex media background and allows the quantification of metabolically active spores and the monitoring of spore germination. A distinction of germinated spores and not germinated spores was based on logistic regression, using multiparameteric data from flow cytometry. In a first step, a significant correlation between colony-forming unit (CFU) counts and viable spore concentration (1) in an industrially relevant model bioprocess was found. Spore germination (2) was followed over the initial process phase with close temporal resolution. The validation of the method showed an error below 5 %. Differences in spore germination for various spore inocula ages and spore inoculum concentrations were monitored. The real-time applicability of the method suggests the implementation as a PAT tool in filamentous bioprocesses.

  17. Prevention of Preharvest Sprouting through Hormone Engineering and Germination Recovery by Chemical Biology

    Science.gov (United States)

    Nonogaki, Mariko; Nonogaki, Hiroyuki

    2017-01-01

    Vivipary, germination of seeds on the maternal plant, is observed in nature and provides ecological advantages in certain wild species, such as mangroves. However, precocious seed germination in agricultural species, such as preharvest sprouting (PHS) in cereals, is a serious issue for food security. PHS reduces grain quality and causes economical losses to farmers. PHS can be prevented by translating the basic knowledge of hormone biology in seeds into technologies. Biosynthesis of abscisic acid (ABA), which is an essential hormone for seed dormancy, can be engineered to enhance dormancy and prevent PHS. Enhancing nine-cis-epoxycarotenoid dioxygenase (NCED), a rate-limiting enzyme of ABA biosynthesis, through a chemically induced gene expression system, has successfully been used to suppress germination of Arabidopsis seeds. The more advanced system NCED positive-feedback system, which amplifies ABA biosynthesis in a seed-specific manner without chemical induction, has also been developed. The proofs of concept established in the model species are now ready to be applied to crops. A potential problem is recovery of germination from hyperdormant crop grains. Hyperdormancy induced by the NCED systems can be reversed by inducing counteracting genes, such as NCED RNA interference or gibberellin (GA) biosynthesis genes. Alternatively, seed sensitivity to ABA can be modified to rescue germination using the knowledge of chemical biology. ABA antagonists, which were developed recently, have great potential to recover germination from the hyperdormant seeds. Combination of the dormancy-imposing and -releasing approaches will establish a comprehensive technology for PHS prevention and germination recovery.

  18. Responses of quinoa (Chenopodium quinoa Willd. seeds stored under different germination temperatures

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    Andressa Strenske

    2017-01-01

    Full Text Available In this experiment, we assessed the germination and vigor of quinoa seeds packed in paper bags and stored at room temperature for 36, 85, 119, 146, 177 and 270 days. The seeds were harvested under experimental conditions in Marechal Candido Rondon, Paraná, during the 2012/13 growing seasons. Four replicates of 100 seeds each were established for each storage time, and the seeds were evaluated, on paper, based on the BOD under the following experimental temperature conditions: alternating temperatures of 20 and 30°C and a constant temperature of 25°C. The seeds from both treatments were subject to seven-hour photoperiods and 25°C under continuous darkness. The germinated seeds were counted daily for eight days after sowing, and we evaluated the percentages of normal and abnormal seedlings and the germination index. The experimental design was completely randomized using a split-plot design. Increasing the storage time decreased the percentage of germinated seeds and seed vigor due to the increased number of abnormal seedlings. Over the 430-day study period, quinoa seed germination completely declined under the experimental conditions. The final number of germinating seeds should be evaluated 7 days after the beginning of the germination test.

  19. Effect of chemical and physical factors to improve the germination rate of Echinacea angustifolia seeds.

    Science.gov (United States)

    Chuanren, Duan; Bochu, Wang; Wanqian, Liu; Jing, Chen; Jie, Lian; Huan, Zhao

    2004-09-01

    Seeds of Echinacea angustifolia are known for their deep dormancy. In this paper, we studied the responses of E. angustifolia seeds to some chemical and physical factors, such as scarification, chilling (5 degrees C) period, light and applied BA (6-benzylaminopurine), GA3 (gibberellic acid) and sound stimulation. When the seed coat layers were removed, the germination rate grew up from 6 to 20% (incubated in light) and the mean time germination (MTG) was reduced from 18 to 6.6 days. On the basis of layers-removed, chilling and continuous light gave significantly higher germination rate (up to 70%). Compare the data of seeds chilled by 0, 6, 12, 18 and 24 days, the maximum germination rate (up to 70%) achieved at 18-days chilling treatment. Further increases in the chilling period could slightly improve germination. Exogenous application of 0.1, 0.2, 0.3 mg/L GA3 or BA in the previous pretreatment increased germination to 78, 90 and 84% or 76, 86 and 84%, respectively. Obviously, the best concentration of GA or BA is 0.3 mg/L. And the GA3 or BA treatment shortened the MTG to about 4 days. The influence of sound stimulation was also tested in the experiment. The result showed that one 100 dB and 1000 Hz sound wave (sine-wave) was beneficial to the germination of E. angustifolia seeds.

  20. Effects of germination on the nutritional properties, phenolic profiles, and antioxidant activities of buckwheat.

    Science.gov (United States)

    Zhang, Ge; Xu, Zhicun; Gao, Yuanyuan; Huang, Xianxiao; Zou, Yanping; Yang, Tiankui

    2015-05-01

    Germination is considered to be an effective process for improving the nutritional quality and functionality of cereals. In this study, changes of nutritional ingredients, antinutritional components, chemical composition, and antioxidant activities of buckwheat seeds over 72 h of germination were investigated, and the reasons for these changes are discussed. With the prolonged germination time, the contents of crude protein, reducing sugar, total phenolics, total flavonoids, and condensed tannins increased significantly, while the levels of crude fat, phytic acid, and the activity of trypsin inhibitor decreased. Phenolic compounds, such as rutin, vitexin, isovitexin, orientin, isoorientin, chlorogenic acid, trans-3-hydroxycinnamic acid, and p-hydroxybenzoic acid increased significantly during the germination process, which may be due to the activation of phenylalanine ammonialyase. The improvement of flavonoids led to significant enhancement of the antioxidant activities of germinated buckwheat. Germinated buckwheat had better nutritional value and antioxidant activities than ungerminated buckwheat, and it represented an excellent natural source of flavonoids and phenolic compounds, especially rutin and C-glycosylflavones. Therefore, germinated buckwheat could be used as a promising functional food for health promotion.